Methods and compositions for wound healing

ABSTRACT

The present invention relates to methods and compositions for wound healing. In particular, the present invention relates to promoting and enhancing wound healing by utilizing cross-linker covalent modification molecules to attach and deliver wound active agents to a wound. In addition, the present invention provides methods and compositions utilizing oppositely charged polyelectrolytes to form a polyelectrolyte layer on a wound surface. The invention further relates to incorporating wound active agents into a polyelectrolyte layer for delivery to a wound.

This application claims the benefit of U.S. Prov. Appl. 61/303,104,filed Feb. 10, 2010, and is a continuation-in-part of U.S. patentapplication Ser. No. 12/363,044, filed Jan. 30, 2009 now U.S. Pat. No.8,709,393, which claims the benefit of U.S. Prov. Appl. 61/024,725,filed Jan. 30, 2008, the entire contents of which are incorporatedherein by reference.

FIELD OF THE INVENTION

The present invention relates to methods and compositions for themodulation of wound healing. In particular, the present inventionrelates to promoting and enhancing wound healing by changing theintrinsic chemical composition and/or physical features of the woundbed.

BACKGROUND OF THE INVENTION

The primary goal in the treatment of wounds is to achieve wound closure.Open cutaneous wounds represent one major category of wounds and includeburn wounds, wounds resulting from chemical (especially alkali) burns,wounds from physical trauma, neuropathic ulcers, pressure sores, venousstasis ulcers, and diabetic ulcers. Open cutaneous wounds routinely healby a process which comprises six major components: i) inflammation, ii)fibroblast proliferation, iii) blood vessel proliferation, iv)connective tissue synthesis, v) epithelialization, and vi) woundcontraction. Wound healing is impaired when these components, eitherindividually or as a whole, do not function properly. Numerous factorscan affect wound healing, including but not limited to malnutrition,systemic debility due to a variety of causes, wound infection, locallack of progenitor cells, local and/or systemic pharmacological agents(e.g., numerous chemotherapeutic agents, actinomycin and steroids),repeated local trauma, diabetes and other endocrine/metabolic diseases(e.g., Cushing's disease), and advanced age (Hunt and Goodson, 1988,Current Surgical Diagnosis & Treatment, Appleton & Lange, pp. 86-98).Additionally, wounds that are extensive in size, regardless of theinitiating cause, present special challenges due to the large surfacearea that must be re-epithelialized to re-establish surface integrity.

Delayed wound healing causes substantial morbidity in subjects withdiabetes. Diabetes mellitus is a chronic disorder of glucose metabolismand homeostasis that damages many organs. It is the eighth leading causeof death in the United States (Harris et al., 1987, Diabetes 36:523). Inpersons with diabetes, vascular disease, neuropathy, infections, andrecurrent trauma predispose the extremities, especially the foot, topathologic changes. These pathological changes can ultimately lead tochronic ulceration, which may necessitate amputation. Chronic wounds andwounds with pathological or dysregulated healing represent a majorhealth burden and drain on health care resources. Chronic wounds havemajor impacts on the physical and mental health, productivity,morbidity, mortality and cost of care for affected individuals. The mostcommon types of chronic wounds are caused by systemic diseases such asdiabetes, vascular problems such as venous hypertension and byimmobility-induced pressure sores; accounting for 70% of all chronicwounds. Statistics on the prevalence of chronic wounds varies, howeverstudies report that 0.2% to 1% of the population suffer from venousulcers, 0.5% from pressure ulcers, and 5% to 10% of people with diabetesexperience neuropathic ulcers. The economic impact of chronic wounds forthese conditions alone in the United States has been estimated to bewell over $15 billion, annually. With the population growing older,cases of diabetes mellitus will increase as will the magnitude of theproblem associated with chronic wounds in these patients.

Normal wound healing is an enormously complex process involving thecoordinated interplay between fibroblasts, vascular cells, extracellularmatrix and epithelial cells to result in a seamless progression throughan inflammatory reaction, wound repair, contracture and coverage by anepithelial barrier. However, in many patients, due to either the localwound environment or systemic disease or other factors, the woundhealing processes can become asynchronous (i.e., loss of connectivitywith triggering mechanisms associated with prior cellular events) andare unable to progress to closure, resulting in a chronic ulcer.

Wounds that do not readily heal can cause the subject considerablephysical, emotional, and social distress as well as great financialexpense (Richey et al., 1989, Annals of Plastic Surgery 23:159). Indeed,wounds that fail to heal properly and become infected may requireexcision of the affected tissue. A number of treatment modalities havebeen developed as scientists' basic understanding of wounds and woundhealing mechanisms has progressed.

The most commonly used conventional modality to assist in wound healinginvolves the use of wound dressings. In the 1960s, a major breakthroughin wound care occurred when it was discovered that wound healing withmoist, occlusive dressings was, generally speaking, more effective thanthe use of dry, non-occlusive dressings (Winter, 1962, Nature 193:293).Today, numerous types of dressings are routinely used, including films(e.g., polyurethane films), hydrocolloids (hydrophilic colloidalparticles bound to polyurethane foam), hydrogels (cross-linked polymerscontaining about at least 60% water), foams (hydrophilic orhydrophobic), calcium alginates (nonwoven composites of fibers fromcalcium alginate), and cellophane (cellulose with a plasticizer) (Kannonand Garrett, 1995, Dermatol. Surg. 21:583; Davies, 1983, Burns 10:94).Unfortunately, certain types of wounds (e.g., diabetic ulcers, pressuresores) and the wounds of certain subjects (e.g., recipients of exogenouscorticosteroids) do not heal in a timely manner (or at all) with the useof such dressings.

Several pharmaceutical modalities have also been utilized in an attemptto improve wound healing. For example, some practitioners have utilizedtreatment regimens involving zinc sulfate. However, the efficacy ofthese regimens has been primarily attributed to their reversal of theeffects of sub-normal serum zinc levels (e.g., decreased host resistanceand altered intracellular bactericidal activity) (Riley, 1981, Am. Fam.Physician 24:107). While other vitamin and mineral deficiencies havealso been associated with decreased wound healing (e.g., deficiencies ofvitamins A, C and D; and calcium, magnesium, copper, and iron), there isno strong evidence that increasing the serum levels of these substancesabove their normal levels actually enhances wound healing. Thus, exceptin very limited circumstances, the promotion of wound healing with theseagents has met with little success.

Current clinical approaches used to promote healing in dysregulatedwounds include protection of the wound bed from mechanical trauma (e.g.splinting, bandaging), meticulous control of surface microbial burden(antibiotics, antimicrobial peptides, bacteriophages, antiseptics andother antimicrobial compounds that broadly inhibit wound pathogens(e.g., silver sulfadiazine) combined with topical application of solublecytoactive factors (e.g. growth factors exemplified by but not limitedto epidermal growth factor-EGF, exogenous extracellular matrixconstituents such as fibronectin), surgical excision of the wound marginor entire bed and surgical placement of tissue flaps and/or autografts,allografts and xenografts. All of these approaches fall short ofpromoting optimal healing conditions in many of the most challengingwounds. It is likely that a major contributing factor to the failure ofthese traditional approaches is the fact that they do not alter theintrinsic chemistry/structure of the wound bed itself that has beenshown in many cases to contribute significantly to their persistence.Additionally, the historical use of a single factor or set of factors totreat all wounds often falls short due to the great heterogeneity foundin wound beds themselves and the complex environment of the wound itselfcontaining a community of signaling molecules that frequently modulatethe activity of individual molecules.

Of broad-spectrum bactericidal agents, silver is considered particularlyfavorable because the likelihood of developing bacterial resistance tosilver is believed to be very low; therefore, it can be employed as abactericidal agent continuously. However, currently available methods ofapplying silver as a bactericidal agent for wound treatment areinadequate. For example, 0.5% silver nitrate solution is a standard andpopular agent for topical burn wound therapy, providing a beneficialeffect in decreasing wound surface inflammation. However, while suchformulations have a high concentration of silver, there is no residualactivity, necessitating frequent applications (e.g., up to 12 times aday) which poses a severe logistical burden in clinical settings. Silverions released through use of 0.5% silver nitrate solution become rapidlyinactive through formation of chemical complexes by chloride within 2hours. Frequent dressings also result in large excesses of silver beingdelivered to the wound, causing wound-discoloration and toxic effects(Dunn et al., 2004, Burns 30(supplement 1):S1; herein incorporated byreference in its entirety). Additionally, nitrate is toxic to wounds andto mammalian cells. The reduction of nitrate to nitrite further causesoxidant-induced damage to cells, which is cited as the most likelyreason for the impaired re-epithelialization with use of silver nitratesolution in partial thickness burns or donor sites.

Silver compounds such as silver sulfadiazine in cream formulations(e.g., Flammazine®, Silvadene®) have also been used for wound treatment.However, such formulations also have limited residual activity and haveto be applied twice a day. Bacterial resistance does develop to theseformulations, and, impaired re-epithelialization has also been observed.Bone marrow toxicity has been observed with silver sulfadiazine,primarily due to its propylene glycol component.

Additionally, in some methods, silver itself is incorporated into thedressing instead of being applied as a separate formulation. Controlledand prolonged release of silver to the wound allows dressings to bechanged less frequently. However, dressings have to be impregnated withlarge amount of silver, which results in cytotoxicity to mammaliancells. Silver released from a commercially available wound-dressing(Acticoat™) containing nanocrystalline silver (Dunn et al., 2004, Burns30(supplement 1):S1; herein incorporated by reference in its entirety)is toxic to in vitro monolayer cell cultures of keratinocytes andfibroblasts (Poon et al., 2004, Burns 30:140; Trop et al., 2006, J.Trauma 60:648; each herein incorporated by reference in its entirety).

The complex nature of pathologic wounds, and the lack of significantclinical progress based on current therapies, indicates the urgent needfor new and unconventional approaches. What is needed is are safe,effective, and interactive means for enhancing the healing of chronicand severe wounds. The methods should be adaptable without regard to thetype of wound, or the nature of the patient population, to which thesubject belongs.

SUMMARY OF THE INVENTION

The present invention relates to methods and compositions for themodulation of wound healing. In particular, the present inventionrelates to promoting and enhancing wound healing by changing theintrinsic chemical composition and/or physical attributes of the woundbed. Accordingly, in some embodiments the present invention providesformulations that alter the physical attributes (compliance, topography,charge), as well as cross-linker covalent modification molecules toattach and deliver antimicrobial compounds as well as extracellularmatrices and other scaffolds and cytoactive agents to a wound. Inaddition, the present invention provides methods and compositionsutilizing oppositely charged polyelectrolytes to form a polyelectrolytelayer on a wound surface. The invention further relates to theincorporation of non-charged polymers into the wound bed viainteractions such as but not limited to hydrogen bonding. The scope ofthe invention includes incorporation of nanoparticles and microparticlesinto the wound bed to engineer the physical characteristics and chemicalcomposition of the wound bed. The invention further relates toincorporating wound active agents into a polyelectrolyte layer,nanoparticle or microparticle for delivery to a wound. In someembodiments, the present invention provides formulations that promote afavorable and stable pH, surface charge, surface energy, osmoticenvironment, surface functionalities that enhance galvano and magnetopositive effects on wound healing, supply of nitric oxide, provideenergy sources for cells and/or provide a balance of MMP/otherpeptidase/protease activity.

The present invention further relates to providing compositions,methods, and kits comprising selectively toxic wound active agents thatare highly bactericidal but that support growth and viability ofmammalian cells (e.g., keratinocytes, neurons, vascular endothelialcells and fibroblasts cells). In preferred embodiments, the wound activeagent is silver, including but not limited to silver nanoparticles. Inparticularly preferred embodiments, the silver loading of someembodiments of the present invention is between 0.35 and 0.4 μg/cm².Polyelectrolyte thin films of the present invention comprising silver(e.g., silver nanoparticles) find use in the treatment of wounds and theprevention of infection, including but not limited to as coatings ondevices that come partially, directly, indirectly, or completely incontact with the body of a subject (e.g., a human patient).

In one embodiment, the compositions and methods of the present inventionprovide approaches to promote healing in pathologic wounds by alteringthe surface chemistry and structure of the pathologic wound bed itselfso as to ultimately enable differential modulation of key cellularelements customizable to the specific patient's health wound type andanatomic location in a subject.

In one embodiment, the present invention provides for the covalentimmobilization of factors to the wound bed. In some embodiments, thepresent invention provides methods of treatment, comprising providing asubject having a wound, at least one covalent modification agent and atleast one wound active agent, and contacting the wound with the at leastone covalent modification agent and the at least one wound active agentunder conditions such that the at least one wound active agent iscovalently attached to the wound. In some embodiments, the subject is ahuman. In other embodiments, the subject is a non-human vertebrate. Insome embodiments, the at least one covalent modification agent is ahomobifunctional cross-linker. In other embodiments, the at least onecovalent modification agent is a heterobifunctional cross-linker. Forexample, in some embodiments, the homobifunctional cross-linker is anN-hydroxysuccinimidyl ester (e.g., including, but not limited to,disuccinimidyl ester, dithiobis(succinimidylpropionate),3,3′-dithiobis(sulfosuccinimidylpropionate), disuccinimidyl suberate,bis(sulfosuccinimidyl)suberate, disuccinimidyl tartarate,disulfosuccinimidyl tartarate,bis[2-(succinimidyloxycarbonyloxy)ethyl]sulfone,bis[2-(sulfosuccinimidooxycarbonyloxy)ethyl]sulfone, ethyleneglycolbis(succinimidylsuccinate), ethyleneglycolbis(sulfosuccinimidylsuccinate), disuccinimidyl glutarate, andN,N′-disuccinimidylcarbonate). In some embodiments, the homobifunctionalcross-linker is at a concentration between 1 nanomolar and 10millimolar. In some preferred embodiments, the homobifunctionalcross-linker is at a concentration between 10 micromolar and 1millimolar. In other embodiments, the at least one covalent modificationagent is a heterobifunctional cross-linker (e.g., including, but notlimited to, N-succinimidyl 3-(2-pyridyldithio)propionate, succinimidyl6-(3-[2-pyridyldithio]-propionamido)hexanoate, sulfosuccinimidyl6-(3′-[2-pyridyldithio]-propionamido)hexanoate,succinimidyloxycarbonyl-α-methyl-α-(2-pyridyldithio)toluene,sulfosuccinimidyl-6-[α-methyl-α-(2-pyridyldithio)toluamido]hexanoate,succinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate,sulfosuccinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate,m-maleimidobenzoyl-N-hydroxysuccinimide ester,m-maleimidobenzoyl-N-hydroxy-sulfosuccinimide ester,N-succinimidyl(4-iodoacetyl)aminobenzoate,sulfo-succinimidyl(4-iodoacetyl)aminobenzoate,succinimidyl-4-(p-maleimidophenyl)butyrate,sulfosuccinimidyl-4-(p-maleimidophenyl)butyrate,N-(γ-maleimidobutyryloxy)succinimide ester,N-(γ-maleimidobutyryloxy)sulfosuccinimide ester, succinimidyl6-((iodoacetyl)amino)hexanoate, succinimidyl6-(6-(((4-iodoacetyl)amino)hexanoyl)amino)hexanoate, succinimidyl4-(((iodoacetyl)amino)methyl)cyclohexane-1-carboxylate, succinimidyl6-((((4-iodoacetyl)amino)methyl)cyclohexane-1-carbonyl)amino)-hexanoate,and p-nitrophenyl iodoacetate). In some embodiments, theheterobifunctional cross-linker is modified with functional groups,rendering it soluble in aqueous solvents for delivery as an aqueoussolution. Furthermore, in some embodiments, the aqueous solutioncontains additives (e.g., including, but not limited to, surfactants andblock copolymers). In other embodiments, a multiplicity ofhetero-bifunctional cross-linkers can be attached to a molecule, polymeror particle to serve as the crosslinking agent. In other embodiments,the heterobifunctional cross-linker is dissolved in an organic solvent(e.g., including, but not limited to, dimethyl sulfoxide). In someembodiments, the at least one wound active agent includes, but is notlimited to, trophic factors, extracellular matrices, enzymes, enzymeinhibitors, defensins, polypeptides, anti-infective agents, bufferingagents, vitamins and minerals, analgesics, anticoagulants, coagulationfactors, anti-inflammatory agents, vasoconstrictors, vasodilators,diuretics, and anti-cancer agents. In some embodiments, the at least onewound active agent contains one or more free —SH groups.

The present invention also provides a kit for treating a subject havinga wound, comprising at least one covalent modification agent, at leastone wound active agent, and instructions for using the kit to covalentlylink the at least one wound active agent to the wound. In someembodiments, the at least one covalent modification agent is ahomobifunctional cross-linker. In some embodiments, the homobifunctionalcross-linker is an N-hydroxysuccinimidyl ester (e.g., including, but notlimited to, disuccinimidyl ester, dithiobis(succinimidylpropionate),3,3′-dithiobis(sulfosuccinimidylpropionate), disuccinimidyl suberate,bis(sulfosuccinimidyl)suberate, disuccinimidyl tartarate,disulfosuccinimidyl tartarate,bis[2-(succinimidyloxycarbonyloxy)ethyl]sulfone,bis[2-(sulfosuccinimidooxycarbonyloxy)ethyl]sulfone, ethyleneglycolbis(succinimidylsuccinate), ethyleneglycolbis(sulfosuccinimidylsuccinate), disuccinimidyl glutarate, andN,N′-disuccinimidylcarbonate). In some embodiments, the at least onecovalent modification agent is a heterobifunctional cross-linker (e.g.,including, but not limited to, N-succinimidyl3-(2-pyridyldithio)propionate, succinimidyl6-(3-[2-pyridyldithio]-propionamido)hexanoate, sulfosuccinimidyl6-(3′-[2-pyridyldithio]-propionamido)hexanoate,succinimidyloxycarbonyl-α-methyl-α-(2-pyridyldithio)toluene,sulfosuccinimidyl-6-[α-methyl-α-(2-pyridyldithio)toluamido]hexanoate,succinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate,sulfosuccinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate,m-maleimidobenzoyl-N-hydroxysuccinimide ester,m-maleimidobenzoyl-N-hydroxy-sulfosuccinimide ester,N-succinimidyl(4-iodoacetyl)aminobenzoate,sulfo-succinimidyl(4-iodoacetyl)aminobenzoate,succinimidyl-4-(p-maleimidophenyl)butyrate,sulfosuccinimidyl-4-(p-maleimidophenyl)butyrate,N-(γ-maleimidobutyryloxy)succinimide ester,N-(γ-maleimidobutyryloxy)sulfosuccinimide ester, succinimidyl6-((iodoacetyl)amino)hexanoate, succinimidyl6-(6-(((4-iodoacetyl)amino)hexanoyl)amino)hexanoate, succinimidyl4-(((iodoacetyl)amino)methyl)cyclohexane-1-carboxylate, succinimidyl6-((((4-iodoacetyl)amino)methyl)cyclohexane-1-carbonyl)amino)-hexanoate,and p-nitrophenyl iodoacetate). In some embodiments, the at least onewound active agent includes, but is not limited to, trophic factors(including polypeptide growth factors, neuropeptides, neurotrophins,extracellular matrices and their individual native constituents(exemplified by but not limited to laminin, fibronectin, vitronectin,collagens, also select amino acid sequences found in these proteinsknown to promote cell behaviors favorable to wound healing e.g.,integrin binding sequences exemplified by but not limited to RGD, EILDV,VCAM-1 and their recombined or synthetic analogs, enzymes, enzymeinhibitors, polypeptides, antimicrobial peptides (exemplified by but notlimited to defensins, magaignins, cathelocidins, bactenicin)anti-infective agents including silver containing compounds (e.g., ionicsilver, elemental silver, silver nanoparticles, and formulationsthereof), buffering agents, vitamins and minerals, compounds thatpromote generation/stabilization of nitric oxide, energy sources forcells, analgesics, anticoagulants, coagulation factors,anti-inflammatory agents, vasoconstrictors, vasodilators, diuretics, andanti-cancer agents. In other embodiments the kits include smallinterfering RNAs (siRNAs-also referred to as micro RNAs) that arecapable of promoting cellular behaviors conducive to the wound healingprocess. In other embodiments, the kits include compounds thatpromote/stabilize a favorable pH, osmotic environment, surface energy,surface charge, surface functionalities that enhance galvano and magnetopositive effects on wound healing, or balance of MMP/otherpeptidase/protease activity.

In some embodiments, the present invention provides a method oftreatment, comprising providing a subject having a wound, at least onecationic polyelectrolyte, at least one anionic polyelectrolyte, at leastone covalent modification agent, and at least one wound active agent,and contacting the wound with the at least one cationic and the at leastone anionic polyelectrolytes, the at least one covalent modificationagent, and the at least one wound active agent so that the at least onewound active agent is covalently linked to the wound by incorporationinto a polyelectrolyte layer formed by the at least one cationic and theat least one anionic polyelectrolytes. In some preferred embodiments,the polyelectrolytes are sequentially and repeatedly layered on thewound, then the at least one covalent modification agent and the atleast one wound active agent are added. In some embodiments, the atleast one cationic polyelectrolyte (e.g., including, but not limited to,poly(L-lysine), poly(ethylene imine), and poly(allylamine hydrochlorideand dendrimers and multi-armed polymers that present multiple aminegroups) is the top layer of the polyelectrolyte layers. Furthermore, insome embodiments, the at least one cationic polyelectrolyte harbors aprimary amine group which allows attachment of the at least one covalentmodification agent to the at least one cationic polyelectrolyte. Forexample, in some preferred embodiments, the at least one cationicpolyelectrolyte is polylysine and the at least one anionicpolyelectrolyte is polyglutamic acid. In some embodiments, the at leastone anionic polyelectrolyte (e.g., including, but not limited to,poly(L-glutamic acid), poly(sodium 4-styrenesulfonate), poly(acrylicacid), poly(maleic acid-co-propylene), hyaluronic acid, chondroitin, andpoly(vinyl sulfate)) is the top layer of the polyelectrolyte layers. Ina preferred embodiment, the at least one anionic polyelectrolyte ispolyglutamic acid. In some embodiments, the at least one covalentmodification agent is a heterobifunctional cross-linker (e.g.,including, but not limited to, N-succinimidyl3-(2-pyridyldithio)propionate, succinimidyl6-(3-[2-pyridyldithio]-propionamido)hexanoate, sulfosuccinimidyl6-(3′-[2-pyridyldithio]-propionamido)hexanoate,succinimidyloxycarbonyl-α-methyl-α-(2-pyridyldithio)toluene,sulfosuccinimidyl-64α-methyl-α-(2-pyridyldithio)toluamido]hexanoate,succinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate,sulfosuccinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate,m-maleimidobenzoyl-N-hydroxysuccinimide ester,m-maleimidobenzoyl-N-hydroxy-sulfosuccinimide ester,N-succinimidyl(4-iodoacetyl)aminobenzoate,sulfo-succinimidyl(4-iodoacetyl)aminobenzoate,succinimidyl-4-(p-maleimidophenyl)butyrate,sulfosuccinimidyl-4-(p-maleimidophenyl)butyrate,N-(γ-maleimidobutyryloxy)succinimide ester,N-(γ-maleimidobutyryloxy)sulfosuccinimide ester, succinimidyl6-((iodoacetyl)amino)hexanoate, succinimidyl6-(6-(((4-iodoacetyl)amino)hexanoyl)amino)hexanoate, succinimidyl4-(((iodoacetyl)amino)methyl)cyclohexane-1-carboxylate, succinimidyl6-((((4-iodoacetyl)amino)methyl)cyclohexane-1-carbonyl)amino)-hexanoate,and p-nitrophenyl iodoacetate). In some embodiments, the at least onecovalent modification agent is a homobifunctional cross-linker In someembodiments, the homobifunctional cross-linker is anN-hydroxysuccinimidyl ester (e.g., including, but not limited to,disuccinimidyl ester, dithiobis(succinimidylpropionate),3,3′-dithiobis(sulfosuccinimidylpropionate), disuccinimidyl suberate,bis(sulfosuccinimidyl)suberate, disuccinimidyl tartarate,disulfosuccinimidyl tartarate,bis[2-(succinimidyloxycarbonyloxy)ethyl]sulfone,bis[2-(sulfosuccinimidooxycarbonyloxy)ethyl]sulfone, ethyleneglycolbis(succinimidylsuccinate), ethyleneglycolbis(sulfosuccinimidylsuccinate), disuccinimidyl glutarate, andN,N′-disuccinimidylcarbonate). In some embodiments, the at least onecovalent modification agent can be at a concentration between 1nanomolar and 10 millimolar. In some preferred embodiments, the at leastone covalent modification agent is at a concentration between 10micromolar to 1 millimolar. In some preferred embodiments, the at leastone covalent modification agent is bis(sulfosuccinimidyl)suberate (forexample, in aqueous solution at a concentration between 1 nM and 10 mM).In some embodiments, the at least one covalent modification agentcomprises N-hydroxysuccinimidyl ester. In some preferred embodiments,the at least one wound active agent contains the peptide sequencegly-arg-gly-asp-ser-pro-lys.

In some embodiments, a first at least one anionic or cationicpolyelectrolyte is contacted with the at least one covalent modificationagent and the at least one wound active agent before contacting with thewound bed and oppositely charged at least one cationic or anionicpolyelectrolyte. In some preferred embodiments, the first at least oneanionic polyelectrolyte is polyglutamic acid, the at least one covalentmodification agent is N-hydroxysuccinimidyl ester, and the at least onewound active agent contains a primary amine (e.g., including, but notlimited to, the peptide sequence gly-arg-gly-asp-ser-pro-lys). In somepreferred embodiments, the first at least one cationic polyelectrolyteis polylysine, the at least one covalent modification agent isN-succinimidyl 3-(2-pyridyldithio)propionate, and the at least one woundactive agent contains the peptide sequence gly-arg-gly-asp-ser-pro-cys.

The present invention further provides kits for treating a subjecthaving a wound, comprising at least one cationic polyelectrolyte, atleast one anionic polyelectrolyte, at least one covalent modificationagent, at least one wound active agent; and instructions for using thekit to covalently link the at least one wound active agent to the woundby incorporation into a polyelectrolyte layer that is formed by the atleast one cationic and anionic polyelectrolytes. In some embodiments,the incorporation of the at least one wound active agent is achieved bysequential and repeated layering of the polyelectrolytes, followed byaddition of the at least one covalent modification agent and the atleast one wound active agent. In other embodiments, a first at least oneanionic or cationic polyelectrolyte is contacted with the at least onecovalent modification agent and the at least one wound active agentbefore contacting with the wound bed and oppositely charged at least onecationic or anionic polyelectrolyte. In some embodiments, the at leastone cationic polyelectrolyte includes, but is not limited to,poly(L-lysine), poly(ethylene imine), and poly(allylaminehydrochloride). In some embodiments, the at least one anionicpolyelectrolyte includes, but is not limited to, poly(L-glutamic acid),poly(sodium 4-styrenesulfonate), poly(acrylic acid), poly(maleicacid-co-propylene), and poly(vinyl sulfate). In some embodiments, the atleast one covalent modification agent is a homobifunctionalcross-linker. In some embodiments, the homobifunctional cross-linker isan N-hydroxysuccinimidyl ester (e.g., including, but not limited to,disuccinimidyl ester, dithiobis(succinimidylpropionate),3,3′-dithiobis(sulfosuccinimidylpropionate), disuccinimidyl suberate,bis(sulfosuccinimidyl)suberate, disuccinimidyl tartarate,disulfosuccinimidyl tartarate,bis[2-(succinimidyloxycarbonyloxy)ethyl]sulfone,bis[2-(sulfosuccinimidooxycarbonyloxy)ethyl]sulfone, ethyleneglycolbis(succinimidylsuccinate), ethyleneglycolbis(sulfosuccinimidylsuccinate), disuccinimidyl glutarate, andN,N′-disuccinimidylcarbonate). In other embodiments, the at least onecovalent modification agent is a heterobifunctional cross-linker (e.g.,including, but not limited to, N-succinimidyl3-(2-pyridyldithio)propionate, succinimidyl6-(3-[2-pyridyldithio]-propionamido)hexanoate, sulfosuccinimidyl6-(3′-[2-pyridyldithio]-propionamido)hexanoate,succinimidyloxycarbonyl-α-methyl-α-(2-pyridyldithio)toluene,sulfosuccinimidyl-6-[α-methyl-α-(2-pyridyldithio)toluamido]hexanoate,succinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate,sulfosuccinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate,m-maleimidobenzoyl-N-hydroxysuccinimide ester,m-maleimidobenzoyl-N-hydroxy-sulfosuccinimide ester,N-succinimidyl(4-iodoacetyl)aminobenzoate,sulfo-succinimidyl(4-iodoacetyl)aminobenzoate,succinimidyl-4-(p-maleimidophenyl)butyrate,sulfosuccinimidyl-4-(p-maleimidophenyl)butyrate,N-(γ-maleimidobutyryloxy)succinimide ester,N-(γ-maleimidobutyryloxy)sulfosuccinimide ester, succinimidyl6-((iodoacetyl)amino)hexanoate, succinimidyl6-(6-(((4-iodoacetyl)amino)hexanoyl)amino)hexanoate, succinimidyl4-(((iodoacetyl)amino)methyl)cyclohexane-1-carboxylate, succinimidyl6-((((4-iodoacetyl)amino)methyl)cyclohexane-1-carbonyl)amino)-hexanoate,and p-nitrophenyl iodoacetate). In some embodiments, the at least onewound active agent includes, but is not limited to, trophic factors,extracellular matrices, enzymes, enzyme inhibitors, defensins,polypeptides, anti-infective agents (including but not limited to silver(e.g., ionic silver, elemental silver, silver nanoparticles, andformulations thereof)), buffering agents, vitamins and minerals,analgesics, anticoagulants, coagulation factors, anti-inflammatoryagents, vasoconstrictors, vasodilators, diuretics, and anti-canceragents.

The present invention also provides a method of treatment, comprisingproviding a subject having a wound, at least one cationicpolyelectrolyte, at least one anionic polyelectrolyte, at least one DNAdelivery agent, and at least one DNA species, and contacting the woundwith the at least one cationic polyelectrolyte, the at least one anionicpolyelectrolyte, the at least one DNA delivery agent, and the at leastone DNA species under conditions such that the at least one DNA speciesis delivered to the wound. In some preferred embodiments, the at leastone DNA species includes, but is not limited to, DNA encoding vascularendothelial growth factor and/or epidermal growth factor. In somepreferred embodiments, the at least one cationic polyelectrolyte ispolylysine. In some embodiments, the method further comprises contactingthe wound with an additional wound active agent (including but notlimited to an anti-infective agent (e.g., ionic silver, elementalsilver, silver nanoparticles, and formulations thereof.)

The present invention further provides a kit for treating a subjecthaving a wound, comprising: at least one cationic polyelectrolyte, atleast one anionic polyelectrolyte, at least one DNA delivery agent, atleast one DNA species, and instructions for using the kit to deliver theat least one DNA species to the wound using the at least one DNAdelivery agent and a polyelectrolyte layer formed by the at least onecationic and anionic polyelectrolytes. In some embodiments, the kitfurther comprises an additional wound active agent (including but notlimited to an anti-infective agent (e.g., ionic silver, elementalsilver, silver nanoparticles, and formulations thereof.)

The present invention also provides a method of treatment, comprisingproviding a subject having a wound, a cationic and anionicpolyelectrolyte mixture, a deprotection agent, at least one covalentmodification agent, and at least one wound active agent; contacting thewound with the polyelectrolyte mixture to form a polyelectrolyte layeron the wound; applying the deprotection agent to the polyelectrolytelayer to form a deprotected polyelectrolyte layer; applying the at leastone covalent modification agent to the deprotected polyelectrolyte layerto form a modified deprotected polyelectrolyte layer; and applying theat least one wound active agent to the modified deprotectedpolyelectrolyte layer under conditions such that the at least one woundactive agent is covalently attached to the wound. In some preferredembodiments, the anionic and cationic polyelectrolyte mixture is made upof polylactic acid and poly(epsilon-CBZ-L-lysine), blended at an 80:20ratio. In some embodiments, the deprotection occurs by acid hydrolysis.In some embodiments, the at least one covalent modification agent isSP3. The present invention also provides a composition comprising adeprotected polyelectrolyte, functionalized with at least one covalentmodification agent containing an active group that is exposable to atleast one wound active agent. In some preferred embodiments, thedeprotected polyelectrolyte is comprised of polylactic acid andpoly(epsilon-CBZ-L-lysine), blended at an 80:20 ratio. In a preferredembodiment, the at least one covalent modification agent is SP3.

The present invention also provides a method of treatment, comprisingproviding a subject having a wound, a cationic and anionicpolyelectrolyte mixture, a deprotection agent, at least one covalentmodification agent, a first polypeptide, and at least one wound activeagent linked to a second polypeptide; contacting the wound with thepolyelectrolyte mixture to form a polyelectrolyte layer on the wound;applying the deprotection agent to the polyelectrolyte layer to form adeprotected polyelectrolyte layer; applying the at least one covalentmodification agent to the deprotected polyelectrolyte layer to form amodified deprotected polyelectrolyte layer; applying the firstpolypeptide to the modified deprotected polyelectrolyte layer tocovalently link the first polypeptide to the modified deprotectedpolyelectrolyte layer; and applying the at least one wound active agentlinked to the second polypeptide to the modified deprotectedpolyelectrolyte layer covalently linked to the first polypeptide, underconditions such that the at least one wound active agent is attached tothe wound by specific protein binding between the first polypeptide andthe second polypeptide. In some preferred embodiments, the specificprotein binding occurs between biotin and a polypeptide (e.g.,including, but not limited to, avidin, neutravidin, and streptavidin).In other preferred embodiments, the specific protein binding occursbetween glutathione-S-transferase and glutathione. In yet otherpreferred embodiments, the specific protein binding occurs betweennickel-nitrilotriacetic acid and polyhistidine. In some embodiments, theat least one covalent modification agent is SP3.

The present invention further provides a composition comprising adeprotected polyelectrolyte functionalized with at least one covalentmodification agent linked to a first polypeptide that interacts byspecific binding with a second polypeptide linked to at least one woundactive agent. In some preferred embodiments, the specific binding occursbetween biotin and a polypeptide (e.g., including, but not limited to,avidin, neutravidin, and streptavidin). In other preferred embodiments,the specific binding occurs between glutathione-S-transferase andglutathione. In still other preferred embodiments, the specific proteinbinding occurs between nickel-nitrilotriacetic acid and polyhistidine.

The present invention also provides a method of treatment, comprisingproviding a subject having a wound, a cationic and anionicpolyelectrolyte mixture, a deprotection agent, at least one covalentmodification agent, at least one molecule containing an azide group, andat least one wound active agent containing an alkyne group; contactingthe wound with the polyelectrolyte mixture to form a polyelectrolytelayer on the wound; applying the deprotection agent to thepolyelectrolyte layer to form a deprotected polyelectrolyte layer;applying the at least one covalent modification agent to the deprotectedpolyelectrolyte layer to form a modified deprotected polyelectrolytelayer; applying the at least one molecule containing an azide group tothe modified deprotected polyelectrolyte layer to covalently link the atleast one molecule containing an azide group to the modified deprotectedpolyelectrolyte layer; and applying the at least one wound active agentcontaining an alkyne group to the modified deprotected polyelectrolytelayer covalently linked to the at least one molecule containing an azidegroup, so that the at least one wound active agent is attached to thewound by click chemistry. In some preferred embodiments, the at leastone molecule containing an azide group has the formula H₂N(CH₂CH₂O)₂N₃.In some preferred embodiments, the at least one wound active agent isL-propargylglycine. In some preferred embodiments, the reaction iscarried out in the presence of Cu(I).

The present invention further provides a composition comprising adeprotected polyelectrolyte functionalized with at least one covalentmodification agent linked to at least one molecule containing an azidegroup that is attached by click chemistry to at least one wound activeagent containing an alkyne group.

The present invention further provides a kit for treating a subjecthaving a wound, comprising a cationic and anionic polyelectrolytemixture, a deprotection agent, at least one covalent modification agent,at least one wound active agent, and instructions for using the kit tocovalently link the at least one wound active agent to the wound bydeprotection of the polyelectrolyte mixture contacted to the wound,followed by addition of the at least one covalent modification agent andthe at least one wound active agent. In some preferred embodiments, thepolyelectrolyte mixture comprises polylactic acid andpoly(epsilon-CBZ-L-lysine). In some preferred embodiments, thedeprotection agent causes deprotection by acid hydrolysis of thepolyelectrolyte mixture. In some preferred embodiments, the at least onecovalent modification agent is SP3. In some embodiments, the kit alsocontains a first and a second polypeptide that interact with each otherby specific protein binding. In some preferred embodiments, the firstpolypeptide is linked to either the at least one covalent modificationagent or the at least one wound active agent and the second polypeptideis linked to the other at least one covalent modification agent or theat least one wound active agent. In some preferred embodiments, thefirst polypeptide is biotin and the second polypeptide is avidin,neutravidin, or streptavidin. In some other preferred embodiments, thefirst polypeptide is glutathione-S-transferase and the secondpolypeptide is glutathione. In still other preferred embodiments, thefirst polypeptide is nickel-nitrilotriacetic acid and the secondpolypeptide is polyhistidine. In some embodiments, the kit contains atleast one molecule containing an azide group that is attached to thepolyelectrolyte mixture after deprotection so that at least one woundactive agent containing an alkyne group can be attached to the wound byclick chemistry.

The present invention further provides a method of treatment, comprisingproviding a subject having a wound, at least one cationicpolyelectrolyte, at least one anionic polyelectrolyte, at least onemodifying agent, and at least one wound active agent containing an aminoterminal cysteine residue; and contacting the wound with thepolyelectrolytes, the at least one modifying agent and the at least onewound active agent so that the at least one wound active agent isattached to the wound by native chemical ligation. In some preferredembodiments, the polyelectrolytes are sequentially and repeatedlylayered on the wound. In some embodiments, the at least one anionicpolyelectrolyte (e.g., including, but not limited to, polyglutamic acid)is the top layer of the polyelectrolyte layers. In some embodiments, theat least one modifying agents are ethylene dichloride and HSCH₂Ph.

The present invention also provides a composition comprising apolyelectrolyte layer that is functionalized with at least one modifyingagent that is exposable to native chemical ligation with at least onewound active agent containing an amino terminal cysteine residue.

The present invention also provides a kit for treating a subject havinga wound, comprising at least one cationic polyelectrolyte, at least oneanionic polyelectrolyte, at least one modifying agent, at least onewound active agent containing an amino terminal cysteine residue, andinstructions for using the kit to form a polyelectrolyte layer on thewound, followed by treatment with the at least one modifying agent andattachment of the at least one wound active agent by native chemicalligation. In some preferred embodiments, the at least one anionicpolyelectrolyte is polyglutamic acid. In some preferred embodiments, theat least one modifying agents are ethylene dichloride and HSCH₂Ph.

In some embodiments, the present invention provides methods of treatmentcomprising: a) providing a subject having a wound, at least one woundmodifying agent, and at least one wound active agent; b) contacting thewound with the at least one wound modification agent to provide amodified wound bed, and c) contacting the modified wound bed with the atleast one wound active agent under conditions such that the at least onewound active agent is incorporated into the modified wound bed andhealing of the wound is enhanced. In some embodiments, the modifiedwound bed is modified to present a functionalized surface reactive withthe at least one wound active agent. In some embodiments, the woundactive agent is applied to the modified wound bed to form a gradient. Insome embodiments, the wound modifying agent alters a property of thewound bed selected from the group consisting of compliance, pH,alkalinity, and oxidative or reductive strength, net charge,hydrophilicity, osmotic strength, nanoscale or submicron topographicfeatures, electroconductivity, MMP production, phagocytosis, andtransglutaminase activity. In some embodiments, the wound modifyingagent is applied to the wound bed by a method selected from the groupconsisting of coating, sprinkling, seeding, electrospinning, spattering,stamping, spraying, pumping, painting, smearing and printing. In someembodiments, the at least one wound modification agent is at least onecrosslinker. In some embodiments, the at least one crosslinker isselected from the group consisting of a homobifunctional crosslinker, aheterobifunctional cross linker, a hetero- and homo-multifunctionalcrosslinker, and a photoactivatable crosslinker and combinationsthereof. In some embodiments, the heterobifunctional crosslinkercomprises an alkyne group. In some embodiments, the wound modifyingagent comprises at least one polymer. In some embodiments, the at leastone polymer is applied to the wound bed to form a polymer multilayer. Insome embodiments, the at least one polymer is selected from the groupconsisting of a cationic polymer, an anionic polymer, a nonionic polymeran amphoteric polymer and combinations thereof. In some embodiments, themethods further comprise contacting the polymer multilayer with acrosslinker to form a functionalized surface reactive with the at leastone wound active agent. In some embodiments, the at least one polymer isa polyelectrolyte multilayer preformed on a support so that thepolyelectrolyte multilayer can be transferred from the support to thewound bed to form a modified wound bed. In some embodiments, the supportis an elastomeric support. In some embodiments, the polymer multilayeris from 1 nm to 250 nm thick. In some embodiments, the polymermultilayer has a compliance of from 3 to 500 kPa. In some embodiments,the wound modifying agent is selected from the group consisting ofnanoparticles and microparticles. In some embodiments, the nano- andmicroparticles are functionalized. In some embodiments, thefunctionalized bead is a mesoscopic cross-linker. In some embodiments,the at least one wound active agent is selected from the groupconsisting of trophic factors, extracellular matrices, enzymes, enzymeinhibitors, defensins, polypeptides, anti-infective agents, bufferingagents, vitamins and minerals, analgesics, anticoagulants, coagulationfactors, anti-inflammatory agents, vasoconstrictors, vasodilators,diuretics, and anti-cancer agents.

In some embodiments, the present invention provides kits for treating asubject having a wound, comprising: a) at least one wound modificationagent, b) at least one wound active agent; and c) instructions for usingthe kit to treat a wound bed with the at least one wound modificationagent to provide a modified wound bed and for incorporating the woundactive agent into the modified wound bed. In some embodiments, the atleast one wound modification agent is selected from the group consistingof a covalent modifying agent, at least one polyelectrolyte,microparticle, nanoparticle, and combinations thereof.

In some embodiments, the present invention provides methods of treatmentcomprising: a) providing a subject having a wound, i) a cationic andanionic polyelectrolyte mixture, ii) a deprotection agent, iii) at leastone covalent modification agent, iv) at least one molecule containing anazide group or alkyne group, and v) at least one wound active agentcontaining the other of an azide group or an alkyne group; b) contactingthe wound with the polyelectrolyte mixture to form a polyelectrolytelayer on the wound; c) applying the deprotection agent to thepolyelectrolyte layer to form a deprotected polyelectrolyte layer; d)applying the at least one covalent modification agent to the deprotectedpolyelectrolyte layer to form a modified deprotected polyelectrolytelayer; e) applying the at least one molecule containing an azide groupor an alkyne group to the modified deprotected polyelectrolyte layer tocovalently link the molecule containing an azide or an alkyne group tothe modified deprotected polyelectrolyte layer; f) applying the at leastone wound active agent containing the other of an azide group or analkyne group to the modified deprotected polyelectrolyte layercovalently linked to the molecule containing an azide group, underconditions such that the at least one wound active agent is attached tothe wound by click chemistry.

In some embodiments, the present invention provides a compositioncomprising a deprotected polyelectrolyte functionalized with at leastone covalent modification agent linked to at least one moleculecontaining an azide group that is attached by click chemistry to atleast one wound active agent containing an alkyne group.

In some embodiments, the present invention provides methods comprisinga) providing a subject having a wound, a plurality of functionalizedbeads and at least one cytoactive factor, b) contacting the at least onecytoactive factor with the at least one functionalized biocompatiblebead such that the at least one cytoactive factor is linked to the atleast one functionalized biocompatible bead and c) applying the at leastone functionalized biocompatible bead linked to the at least onecytoactive factor to a wound bed of the subject.

In some embodiments, the present invention provides methods of treatmentcomprising: a) providing a subject having a wound, at least one polymer,and at least one wound active agent b) applying the at least one polymerto the wound so that a polymer multilayer is formed on the wound; and c)incorporating the at least one wound active agent into the polymermultilayer during application of the at least one polymer, wherein theat least one wound active agent forms a gradient in the polymermultilayer.

In some embodiments, the present invention provides an articlecomprising a matrix formed from a biocompatible material, the matrixcomprising at least one wound active agent, wherein the matrix is from 1to 500 nm in thickness and has a compliance of from 3 to 500 kPa. Insome embodiments, the matrix is functionalized. In some embodiments, thebiocompatible material is selected from the group consisting of proteinsand polymers. In some embodiments, the polymers are selected from thegroup consisting of polyanionic polymers, polycationic polymers,uncharged polymers, and amphoteric polymers and combinations thereof,and wherein the polymers from a multilayer. In some embodiments, theproteins are extracellular matrix proteins selected from the groupconsisting of laminin, vitronectin, fibronection, keratin, collagen, andcombinations thereof. In some embodiments, the matrix is supported by asolid support selected from the group consisting of silicone, siloxaneelastomers, latex, nylon, nylon mesh, biological tissue, silk,polyurethane, Teflon, polyvinyl alcohol membranes, and polyethyleneoxide membranes. In some embodiments, the at least one wound activeagent is distributed on the matrix so that a gradient is formed. In someembodiments, the matrix is at least partially PEGylated. In someembodiments, the present invention provides methods comprising, applyingthe articles described above to a wound on a subject, wherein thearticle enhances healing of the wound. In some embodiments, the presentinvention provides kits comprising the articles described above in asterile package.

In some embodiments of the present invention, the compositions andmethods described above enhance wound healing. The present inventioncontemplates that wound healing may be enhanced in a variety of ways. Insome embodiments, the compositions and methods minimize contracture ofthe wound as to best favor function and cosmesis. In some embodiments,compositions and methods promote wound contracture to best favorfunction and cosmesis. In some embodiments, the compositions and methodspromote vascularization. In some embodiments, the compositions andmethods inhibit vascularization. In some embodiments, the compositionsand methods promote fibrosis. In some embodiments, the compositions andmethods inhibit fibrosis. In some embodiments, the compositions andmethods promote epithelial coverage. In some embodiments, thecompositions and methods inhibit epithelial coverage. In someembodiments, the compositions and methods of the present inventionmodulates one or properties of cells in the wound environment or in theimmediate vicinity of the wound. The properties that are modulated,e.g., are increased or decreased, include, but are not limited toadhesion, migration, proliferation, differentiation, extracellularmatrix secretion, phagocytosis, MMP activity, contraction, andcombinations thereof.

In some embodiments, the present invention provides for the use of anyof the compositions described above or elsewhere herein to enhancehealing of a wound or modulate one or more properties of cells in thewound environment or in the immediate vicinity of the wound. In someembodiments, the present invention provides for the use of a combinationof a wound modifying agent and wound active agent to enhance healing ofa wound to enhance healing of a wound or modulate one or more propertiesof cells in the wound environment or in the immediate vicinity of thewound. In some embodiments, the present invention provides for the useof the articles described above to enhance healing of a wound ormodulate one or more properties of cells in the wound environment or inthe immediate vicinity of the wound.

In some embodiments, the present invention provides an article orcomposition comprising a polymer multilayer comprising at least onepolymer, the polymer multilayer having associated therewith particlesselected from the group consisting of nanoscale and microscaleparticles. In some embodiments, the at least one polymer is selectedfrom the group consisting of a cationic polymer, an anionic polymer, anonionic polymer an amphoteric polymer and combinations thereof. In someembodiments, the polymer multilayer is from 1 nm to 500 nm thick,preferably from 1 nm to 250 nm thick. In some embodiments, the polymermultilayer has a compliance of from 3 kPa to 500 kPa, 3 kPa to 10 MPa,or 3 kPa to 5 GPa. In some embodiments, the particles are polymericparticles. In some embodiments, the particles are selected from thegroup consisting of spherical, ovoid, and cylindrical shaped particles.In some embodiments, the diameter of the particles is greater than thethickness of the polymer multilayer.

In some embodiments, the articles or compositions comprise at least onewound active agent in association with the composition. In someembodiments, the wound active agent is selected from the groupconsisting of antimicrobials, trophic factors, extracellular matrices,enzymes, enzyme inhibitors, defensins, polypeptides, anti-infectiveagents, buffering agents, vitamins and minerals, analgesics,anticoagulants, coagulation factors, anti-inflammatory agents,vasoconstrictors, vasodilators, diuretics, and anti-cancer agents. Insome embodiments, the wound active agent is dispersed in the polymermultilayer. In some embodiments, the wound active agent is covalentlyassociated with the polymer multilayer. In some embodiments, theparticles are functionalized. In some embodiments, the wound activeagent is attached to the particles. In some embodiments, the woundactive agent is contained within the particle.

In some embodiments, the polymer layer is disposed on a support. In someembodiments, the support is a polymeric support. In some embodiments,the polymeric support is a polymer composition that is distinct from thepolymer multilayer. In some embodiments, the polymeric support is anelastomeric polymer. In some embodiments, the polymeric support and thepolymer multilayer are separated by a water soluble material. In someembodiments, the polymeric support is water soluble. In someembodiments, the water soluble support comprises polyvinyl alcohol. Insome embodiments, the support is a wound dressing. In some embodiments,the support is a biologic wound dressing. In some embodiments, thepolymer multilayer is deposited onto the support by a method selectedfrom the group consisting of adsorption from solution and spin coating.

In some embodiments, the particles have an elastic modulus of from about0.5 to about 10 GPa. In some embodiments, the particles are interspersedor dispersed in the polymer multilayer. In some embodiments, theparticles are displayed on a surface of the polymer multilayer. In someembodiments, the particles are underneath the polymer multilayer. Insome embodiments, the particles are between the polymer multilayer andthe support. In some embodiments, the particles are on the surface ofthe polymer multilayer and have a diameter that is greater than thethickness of the polymer multilayer, and wherein the article furthercomprises an antimicrobial silver composition.

In some embodiments, the present invention provides methods of modifyinga surface comprising contacting a surface with a polymer multilayercomprising at least one polymer, the polymer multilayer havingassociated therewith particles selected from the group consisting ofnanoscale and microscale particles under conditions such that thepolymer multilayer is transferred to the surface. In some embodiments,pressure is applied to the polymer multilayer to effect transfer to thesurface. In some embodiments, the pressure is from about 10 to about 500kPa. In some embodiments, the polymer multilayer is disposed on asupport. In some embodiments, the support is from about 1 micrometer toabout 10 mm in thickness. In some embodiments, the surface is a wounddressing. In some embodiments, the wound dressing is a biologic wounddressing. In some embodiments, the polymer multilayer is deposited onthe support by a process selected from the group consisting ofadsorption from solution, spraying, and spin coating. In someembodiments, the support is an elastomeric support. In some embodiments,the surface is a soft or compliant surface. In some embodiments, thesoft surface has an elastic modulus of from about 10 to about 100 kPa.In some embodiments, the soft surface is a biological surface. In someembodiments, the biological surface is selected from the groupconsisting of skin, a wound bed, hair, a tissue surface, and an organsurface. In some embodiments, the biological surface comprises moleculesselected from the group consisting of a proteins, a lipids, acarbohydrates, and combinations thereof. In some embodiments, thesurface comprises (e.g., is coated with or displays) withglycosaminoglycans, collagen and/or hyaluronic acid. In someembodiments, the surface is a surface on a biomedical device. In someembodiments, the surface is a silicone surface. In some embodiments, theat least one polymer is selected from the group consisting of a cationicpolymer, an anionic polymer, a nonionic polymer an amphoteric polymerand combinations thereof. In some embodiments, the polymer multilayer isfrom 1 nm to 500 nm thick. In some embodiments, the polymer multilayerhas a compliance of from 3 kPa to 500 kPa, 3 kPa to 10 MPa, or 3 kPa to5 GPa. In some embodiments, the particles are polymeric particles. Insome embodiments, the diameter of the particles is greater than thethickness of the polymer multilayer. In some embodiments, the particlesare selected from the group consisting of spherical, ovoid, andcylindrical shaped particles. In some embodiments, the polymermultilayer comprises at least one wound active agent. In someembodiments, the wound active agent is selected from the groupconsisting of trophic factors, extracellular matrices, enzymes, enzymeinhibitors, defensins, polypeptides, anti-infective agents, bufferingagents, vitamins and minerals, analgesics, anticoagulants, coagulationfactors, anti-inflammatory agents, vasoconstrictors, vasodilators,diuretics, antimicrobial agents, growth factors, oligopeptides,saccharides, polysaccharides, synthetic molecules comprising abiological moiety, metal particles, electrodes, magnetic particles,honey, and anti-cancer agents. In some embodiments, the wound activeagent is dispersed in the polymer multilayer. In some embodiments, thewound active agent is covalently associated with the polymer multilayer.In some embodiments, the particles are functionalized. In someembodiments, the wound active agent is attached to the particles. Insome embodiments, the particles have an elastic modulus of from about0.5 to about 10 GPa. In some embodiments, the particles are dispersed inthe polymer multilayer. In some embodiments, the particles are displayedon a surface of the polymer multilayer.

In some embodiments, the transfer is done in the substantial absence ofa solution or a liquid solvent. In some embodiments, the transfer is asubstantially or completely dry transfer. In some embodiments, thetransfer is performed through a gas phase. In some embodiments, thetransfer is performed in an environment where the humidity is less than100% of saturation. In some embodiments, the transfer is performed inthe absence of liquid water.

In some embodiments, the present invention provides an article orcomposition comprising a polymer multilayer loaded with an antimicrobialsilver composition in the amount of about 100 to about 500 μg/cm² of thepolymer multilayer and/or having a releasable antimicrobial silvercomposition incorporated therein, wherein the releasable antimicrobialsilver composition is releasable in an amount of about 0.01 and 100μg/cm² of the polymer multilayer per day. In some embodiments, thereleasable antimicrobial silver composition is releasable in an amountof about 0.05 and 100 μg/cm² of the polymer multilayer per day. In someembodiments, the releasable antimicrobial silver composition isreleasable in an amount of about 0.05 and 20 μg/cm² of the polymermultilayer per day. In some embodiments, the antimicrobial silvercomposition is releasable in an amount of about 0.05 and 5 μg/cm² of thepolymer multilayer per day. In some embodiments, the releasableantimicrobial silver composition is releasable in an amount of about0.05 and 2 μg/cm² of the polymer multilayer per day. In someembodiments, the releasable antimicrobial silver composition isreleasable in an amount of about 0.05 and 1 μg/cm² of the polymermultilayer per day. In some embodiments, the releasable antimicrobialsilver composition is releasable in an amount of about 0.1 to 0.5 μg/cm²of the polymer multilayer per day. In some embodiments, theantimicrobial silver composition comprises silver nanoparticles. In someembodiments, the silver nanoparticles are zerovalent silvernanoparticles. In some embodiments, the composition provides at least99.99% killing of Staphylococcus epidermis. In some embodiments, thearticle does not substantially impair the healing of wounds. In someembodiments, the antimicrobial silver composition permits at least 90%viability of NIH-3T3 cells. In some embodiments, the viability isassessed after 24 h of incubation of the NIH-3T3 cells on thecomposition in the presence of growth media. In some embodiments, thearticle is a film. In some embodiments, the article is athree-dimensional object, at least a portion of which is coated with thepolymer multilayer. In some embodiments, the three-dimensional object isa medical device.

In some embodiments, the article is selected from the group consistingof a polymeric support, an elastomeric support, a wound care device, awound dressing and a biologic wound dressing. In some embodiments, themedical device partially contacts a subject. In some embodiments, themedical device is completely implanted in a subject. In someembodiments, the at least one of the polymers comprises poly(allylaminehydrochloride). In some embodiments, at least one of the polymerscomprises poly(acrylic acid). In some embodiments, the articles orcompositions further comprise at least one additional antimicrobialagent.

In some embodiments, the present invention provides a method fortreating a wound comprising providing a subject with a wound andcontacting the wound with an article or composition as described above.

In some embodiments, the present invention provides kits for thetreatment of a wound in a subject, comprising an article or compositionas described above and instructions for applying the article to thewound. In some embodiments, the kits further comprise additional wounddressing material. In some embodiments, the wound dressing material is abiologic wound dressing.

In some embodiments, the present invention provides an article orcomposition comprising a solid support comprising a releasableantimicrobial silver composition, wherein the releasable antimicrobialsilver composition is loaded at an amount of from 1 to about 500 μg/cm²of the solid support and/or releasable in an amount of about 0.01 and100 μg/cm² of the solid support per day. In some embodiments, the solidsupport is selected from the group consisting of a polymeric support, anelastomeric support, nanoparticles, microparticles, a wound dressing anda biologic wound dressing. In some embodiments, the releasableantimicrobial silver composition is releasable in an amount of about0.05 and 100 μg/cm² of the solid support per day. In some embodiments,the releasable antimicrobial silver composition is releasable in anamount of about 0.05 and 20 μg/cm² of the solid support per day. In someembodiments, the releasable antimicrobial silver composition isreleasable in an amount of about 0.05 and 5 μg/cm² of the solid supportper day. In some embodiments, the releasable antimicrobial silvercomposition is releasable in an amount of about 0.05 and 2 μg/cm² of thesolid support per day. In some embodiments, the releasable antimicrobialsilver composition is releasable in an amount of about 0.05 and 1 μg/cm²of the solid support per day. In some embodiments, the releasableantimicrobial silver composition is releasable in an amount of about 0.1to 0.5 μg/cm² of the solid support per day. In some embodiments, theantimicrobial silver composition comprises silver nanoparticles. In someembodiments, the silver nanoparticles are zerovalent silvernanoparticles. In some embodiments, the article does not substantiallyimpair the healing of wounds. In some embodiments, the articles orcompositions further comprise at least one additional antimicrobialagent.

In some embodiments, the present invention provides methods for treatinga wound comprising providing a subject with a wound and contacting thewound with the article or composition as described above.

In some embodiments, the present invention provides methods forsynthesizing a composition for treatment of a wound, comprising: a)assembling alternating layers of polymers to form a film or coating andb) during the assembling, incorporating an antimicrobial silvercomposition into the alternating layers of polymers.

In some embodiments, the present invention provides methods forsynthesizing a composition for treatment of a wound, comprising: a)assembling alternating layers of polymers to form a film or coating; b)incubating the film or coating in bulk solution of a silver salt; c)exposing the film or coating to a reducing agent; and d) selecting filmsor coatings for use having a silver loading level between 0.01 and 100μg/cm². In some embodiments, at least one of the polymers comprises asolution containing poly(allylamine hydrochloride). In some embodiments,at least one of the polymers comprises a solution containingpoly(acrylic acid). In some embodiments, the bulk solution of a silversalt comprises silver nitrate. In some embodiments, the concentration ofAg⁺ in the silver nitrate solution is from 0.005 mM to 5 mM. In someembodiments, the pH of the poly(acrylic acid) solution is from 2.5 to7.5.

In some embodiments, the present invention provides a solid support; anda polymer multilayer supported by the solid support, the polymermultilayer comprising at least one wound active agent. In someembodiments, the article further comprises a water soluble materialbetween the solid support and the polymer multilayer. In someembodiments, the solid support comprises a polymer. In some embodiments,the polymer is an elastomeric polymer. In some embodiments, theelastomeric polymer is a silicon polymer. In some embodiments, thesilicon polymer is selected from the group consisting ofpolydimethylsiloxane and medical grade silicone. In some embodiments,the polymer multilayer has a thickness of from about 1 nm to 500 nm. Insome embodiments, the polymer multilayer has a compliance of from about3 kPa to 5 GPa, preferably about 3 kPa to 500 kPa. In some embodiments,the polymer multilayer comprises nanoscale to microscale particlesincorporated therein. In some embodiments, the particles have a diameterthat is greater than thickness of the polymer multilayer. In someembodiments, the at least one wound active agent is an antimicrobialsilver composition. In some embodiments, the silver loading of thepolyelectrolyte multilayer is between about 0.01 and 500 μg/cm² of theantimicrobial silver composition. In some embodiments, the antimicrobialsilver composition comprises silver nanoparticles. In some embodiments,the silver nanoparticles are zerovalent silver nanoparticles. In someembodiments, the antimicrobial silver composition comprises multivalentsilver ions carried by zirconium phosphate. In some embodiments, thesolid support comprises a material selected from the group consisting ofa foam, a transparent thin film, a hydrogel, hydrofibers, hydrocolloids,alginate fibers, and combinations thereof. In some embodiments, thesolid support comprises a material selected from the group consisting ofsuper absorbent polymers (SAP), silica gel, sodium polyacrylate,potassium polyacrylamides and combinations thereof. In some embodiments,the solid support comprises an absorbent material. In some embodiments,the polymer multilayer is transferred to the support in the substantialabsence of a solvent. In some embodiments, the absorbent material isselected from the group consisting of a fabric, e.g., cotton or nylongauze, and polymer foam. In some embodiments, the absorbent materialcomprises a first surface comprising an anti-adherent material. In someembodiments, the polymer multilayer is deposited on the first surfacecomprising an anti-adherent material. In some embodiments, the absorbentmaterial comprises a second surface fixed to an adhesive material. Insome embodiments, the adhesive material is sized to extend from one ormore edges of the absorbent material so that the absorbent material canbe exposed to the skin of a subject. In some embodiments, the articlefurther comprises a removable sheet, wherein the article is removablyaffixed to the removable sheet. In some embodiments, the article ispackaged in a sterile package. In some embodiments, the polymermultilayer has a thickness of from about 1 nm to 500 nm. In someembodiments, the polymer multilayer has a compliance of from about 3 to500 kPa. In some embodiments, the polymer multilayer comprises nanoscaleto microscale particles incorporated therein. In some embodiments, theat least one wound active agent is an antimicrobial silver composition.In some embodiments, the silver loading of the polyelectrolytemultilayer is between about 0.01 and 500 μg/cm² of the antimicrobialsilver composition. In some embodiments, the antimicrobial silvercomposition comprises silver nanoparticles. In some embodiments, thesilver nanoparticles are selected from the group consisting ofzerovalent silver nanoparticles and multivalent silver ions (carried byzirconium phosphate).

In some embodiments, the solid support comprises a biologic wounddressing. In some embodiments, the biologic wound dressing comprises(e.g., is coated with or displays) a biological molecule selected fromthe group consisting of collagen, hyaluronic acid, glycosaminoglycans,keratin, fibronectin, vitronectin, laminin, and combinations orfragments thereof. In some embodiments, the biopolymer is supported on asilicone film. In some embodiments, the silicone film comprises a fabricsupport. In some embodiments, the fabric support is a nylon fabricsupport. In some embodiments, the polymer multilayer is deposited on thesilicone film. In some embodiments, the polymer multilayer has athickness of from about 1 nm to 500 nm. In some embodiments, the polymermultilayer has a compliance of from about 3 to 500 kPa. In someembodiments, the polymer multilayer comprises nanoscale to microscaleparticles incorporated therein. In some embodiments, the particles havea diameter that is greater than the thickness of the polymer multilayer.In some embodiments, the at least one wound active agent is anantimicrobial silver composition. In some embodiments, the silverloading of the polyelectrolyte multilayer is between about 0.01 and 500μg/cm² of the antimicrobial silver composition. In some embodiments, theantimicrobial silver composition comprises silver nanoparticles. In someembodiments, the silver nanoparticles are selected from the groupconsisting of zerovalent and multivalent silver nanoparticles.

DESCRIPTION OF THE FIGURES

FIG. 1 provides a schematic of a wound bed modified with apolyelectrolyte multilayer.

FIG. 2 provides a schematic of a wound bed modified with covalentmodifying agents.

FIG. 3 exemplifies the covalent immobilization of proteins to modelamine-terminated treated glass surfaces.

FIG. 4 shows ex vivo results for multilayer deposition ofpolyelectrolytes polystyrene sulfonate (PSS) and FITC-labelledpoly(allylamine hydrochloride) (FITC-PAH).

FIG. 5 demonstrates the difference in healing of full thicknesscutaneous wounds in diabetic (db/db) mice compared to control (wildtype) mice.

FIG. 6 is exemplary of the use of beads for healing a wound bed. In thisexample, carboxylic acid-terminated beads are activated outside thewound bed by using NHS and EDC. The activated beads are introduced intothe wound bed and are immobilized in the wound bed via reaction of theactivated surfaces of the beads with amine groups present in the woundbed. Growth factors are introduced into the wound bed and immobilizedvia reaction with the exposed surfaces of the activated beads.

FIG. 7 provides a list of antimicrobial polypeptides, identified by nameand AMSDb database ID number.

FIG. 8 shows the viability of NIH-3T3 mouse fibroblasts after 24 hrincubation in growth media on silver-loaded polyelectrolyte multilayers(PEMs) (Example 13).

FIG. 9 shows viable bacteria detected on silver-loaded PEMs 8 hr afterincubation with 10⁸ cfu/ml of S. epidermidis in buffer. PEMs withvarying silver loading were prepared by incubating them with serialdecimal dilutions of bulk Ag⁺ solution. PEMs incubated with 5 mM Ag⁺(silver nitrate) solution as indicated in this figure contained ˜0.38μg/cm² (where no cytotoxicity towards NIH-3T3 cells was observed in FIG.8), while silver loading in rest of the PEMs was below the detectionlimit of the elemental analysis spectrometer.

FIG. 10 shows NIH 3T3 cells after 24 h incubation on glass surfacescoated with PEMs (10.5 bilayers of PAH_(7.5)/PAA_(x)) without silver(a,c,e) or with silver nanoparticles at concentrations (b) 0.62, (d)0.48, or (f) 0.39 μg/cm². PEMs were prepared with PAA solution of pH 5.5(a, b), or 6.5 (c, d) or 7.5 (e, f).

FIG. 11 provides a schematic depiction of one embodiment of polymermultilayers with microscale beads.

FIG. 12 provides a graph depicting transfer of a polymer multilayercontaining microscale beads to a soft surface as compared to transfer ofa polymer multilayer without microscale beads.

DEFINITIONS

To facilitate an understanding of the invention set forth in thedisclosure that follows, a number of terms are defined below.

The term “wound” refers broadly to injuries to the skin and subcutaneoustissue initiated in different ways (e.g., pressure sores from extendedbed rest and wounds induced by trauma) and with varying characteristics.The methods and compositions described herein are useful for treatmentof all types of wounds, including wounds to internal and externaltissues. Wounds may be classified into one of four grades depending onthe depth of the wound: i) Grade I: wounds limited to the epithelium;ii) Grade II: wounds extending into the dermis; iii) Grade III: woundsextending into the subcutaneous tissue; and iv) Grade IV (orfull-thickness wounds): wounds wherein bones are exposed (e.g., a bonypressure point such as the greater trochanter or the sacrum).

The term “partial thickness wound” refers to wounds that encompassGrades I-III; examples of partial thickness wounds include burn wounds,pressure sores, venous stasis ulcers, and diabetic ulcers. The term“deep wound” is meant to include both Grade III and Grade IV wounds. Thepresent invention contemplates treating all wound types, including deepwounds and chronic wounds.

The term “chronic wound” refers to a wound that has not healed within 30days.

The phrases “promote wound healing,” “enhance wound healing,” and thelike refer to either the induction of the formation of granulationtissue of wound contraction and/or the induction of epithelialization(i.e., the generation of new cells in the epithelium). Wound healing isconveniently measured by decreasing wound area.

The term “wound active agent” refers to known or potential chemicalcompounds that induce a desired pharmacological, physiological effectuseful in the treatment and healing of a wound, wherein the effect maybe prophylactic or therapeutic. The terms also encompasspharmaceutically acceptable, pharmacologically active derivatives ofthose active agents specifically mentioned herein, including, but notlimited to, trophic factors, extracellular matrices, enzymes, enzymeinhibitors, defensins, polypeptides, anti-infective agents (includingbut not limited to ionic silver, elemental silver, and silvernanoparticles), buffering agents, vitamins and minerals, analgesics,anticoagulants, coagulation factors, anti-inflammatory agents,vasoconstrictors, vasodilators, diuretics, and anti-cancer agents.

The term “polymer multilayer” refers to the composition formed bysequential and repeated application of polymer(s) to form a multilayeredstructure. For example, polyelectrolyte multilayers are polymermultilayers are formed by the alternating addition of anionic andcationic polyelectrolytes to a wound or support. The term “polymermultilayer” also refers to the composition formed by sequential andrepeated application of polymer(s) to a wound or to a solid support. Inaddition, the term “polymer layer” can refer to a single layer composedof polymer molecules, such as anionic or cationic polyelectrolytemolecules, existing either as one layer within multiple layers, or as asingle layer of only one type of polyelectrolyte molecules on a wound orsupport. While the delivery of the polymers to the wound bed or supportis sequential in preferred embodiments, the use of the term “polymermultilayer” is not limiting in terms of the resulting structure of thecoating. It is well understood by those skilled in the art thatinter-diffusion of polymers such as polyelectrolytes can take placeleading to structures that may be well-mixed in terms of thedistribution of anionic and cationic polyelectrolytes. It is alsounderstood that the term polyelectrolyte includes polymer species aswell as nanoparticulate species, and that it is not limiting in scopeother than to indicate that the species possesses multiple charged orpartially charged groups. It is also well understood by those skilled inthe art that multilayer structures can be formed through a variety ofinteractions, including electrostatic interactions and others such ashydrogen bonding. Thus, the use of the term “polyelectrolyte” is notlimiting in terms of the interactions leading to the formation of thewound bed constructs.

The term “crosslinked” herein refers to a composition containingintermolecular crosslinks and optionally intramolecular crosslinks aswell, arising from the formation of covalent bonds. Covalent bondingbetween two crosslinkable components may be direct, in which case anatom in one component is directly bound to an atom in the othercomponent, or it may be indirect, through a linking group. A crosslinkedstructure may, in addition to covalent bonds, also includeintermolecular and/or intramolecular noncovalent bonds such as hydrogenbonds and electrostatic (ionic) bonds.

The term “covalent modification agent” refers to any molecule thatcovalently links molecules to each other. Covalent modification agentsinclude homobifunctional and heterobifunctional cross-linkers as well asphotoactivatable cross linkers.

The term “homobifunctional cross-linker” refers to a molecule used tocovalently link identical or similar molecules to each other.Homobifunctional cross-linkers have two identical reactive groups; thus,a homobifunctional cross-linker can only link molecules of the same typeto each other. Conversely, a “heterobifunctional cross-linker” refers toa molecule used to covalently link dissimilar molecules to each other,because it has two or more different reactive groups that can interactwith various molecules of different types. Hetero- andhomo-multifunctional crosslinkers refers to multivalent crosslinkerswith both hetero- and homo-crosslinking functionalities. Activateddendrimers are an example of multifunctional crosslinkers.

The term “subject” refers to any animal (e.g., a mammal), including, butnot limited to, humans, non-human primates, rodents, dogs, cats, and thelike, which is to be the recipient of a particular treatment. Typically,the terms “subject” and “patient” are used interchangeably herein.

The term “surfactant” refers to an amphiphilic material that modifiesthe surface and interface properties of liquids or solids. Surfactantscan reduce the surface tension between two liquids. Detergents, wettingagents, emulsifying agents, dispersion agents, and foam inhibitors areall surfactants.

The term “block copolymer” refers to a polymer consisting of at leasttwo monomers. In a block copolymer, adjacent blocks are constitutionallydifferent, i.e. adjacent blocks comprise constitutional units derivedfrom different species of monomer or from the same species of monomerbut with a different composition or sequence distribution ofconstitutional units. A block copolymer can be thought of as twohomopolymers joined together at the ends.

The term “solvent” refers to a liquid that can dissolve a substance. Theterm “organic solvent” refers to a solvent derived from apetroleum-based product.

The term “polyelectrolyte” refers to a water-soluble macromolecularpolymer substance containing many repeating ionic constituent units,including cations and anions.

The term “primary amine” refers to a derivative of ammonia in which ahydrogen has been replaced by a hydrocarbon unit. Primary amines havethe general formula RNH₂ and examples include, but are not limited to,aniline, methylamine, and 1-propylamine.

The term “DNA delivery agent” refers to any molecule that can bring DNAinto contact with an identified target. In some instances, a DNAdelivery agent causes uptake of DNA into a cell or cells, in vitro or invivo. DNA delivery agents can be viruses including, but not limited to,adenoviruses and retroviruses. DNA delivery agents can also be non-viralagents including, but not limited to, plasmids, lipids, liposomes,polymers and peptides.

The term “exposable” refers to anything that is capable of beingexposed. An exposable surface or molecule is one that is made availableto interaction with other surfaces or molecules. For example, in thecontext of the present invention, a covalent modification agent isexposable to a wound active agent; thus, the two agents can interactwith each other and form covalent bonds.

The term “functionalized” refers to a modification of an existingmolecular segment to generate or introduce a new reactive functionalgroup (e.g., a maleimido or succinimidyl group) that is capable ofundergoing reaction with another functional group (e.g., a sulfhydrylgroup) to form a covalent bond. For example, a component containingcarboxylic acid (—COOH) groups can be functionalized by reaction withN-hydroxy-succinimide or N-hydroxysulfosuccinimide using knownprocedures, to form a new reactive functional group in the form of anactivated carboxylate (which is a reactive electrophilic group), i.e.,an N-hydroxysuccinimide ester or an N-hydroxysulfosuccinimide ester,respectively. In another example, carboxylic acid groups can befunctionalized by reaction with an acyl halide, e.g., an acyl chloride,again using known procedures, to provide a new reactive functional groupin the form of an anhydride.

As used herein, the term “aqueous solution” includes solutions,suspensions, dispersions, colloids, and the like containing water.

As used herein, the term “click chemistry” refers to the use of chemicalbuilding blocks with built-in high-energy content to drive a spontaneousand irreversible linkage reaction with appropriate complementary sitesin other blocks. These chemical reactions (e.g., including, but notlimited to, those between azide and acetylene groups that combinereadily with each other) are specific and result in covalent linkagebetween the two molecules.

The term “native chemical ligation” refers to a chemoselective reactionof two unprotected peptide segments. The reaction results in an initialthioester-linked species, then spontaneous rearrangement of thistransient intermediate occurs, yielding a full-length product with anative peptide bond at the ligation site.

The term “specific protein binding” refers to an interaction between twoor more proteins that have high affinity and specificity for each other.Proteins must bind to specific other proteins in vivo in order tofunction. The proteins are required to bind to only one or a few otherproteins of the few thousand proteins typically present in vivo; theseinteractions are employed in vitro in the present invention to attachwound active agents to the wound. In the context of the presentinvention, specific protein binding interactions include, but are notlimited to, those between biotin and avidin, neutravidin, orstreptavidin; glutathione-S-transferase and glutathione; andnickel-nitrilotriacetic acid and polyhistidine.

The term “device” refers to an object that contacts the body or bodilyfluid of a subject for therapeutic or prophylactic purposes. Somedevices may partially or indirectly contact the body or bodily fluid ofa subject (e.g., catheter, dialysis tubing, diagnostic sensors, drugdelivery devices), while other devices are completely imbedded in orencompassed by the body of a subject (e.g., stent, pacemaker, internallyimplanted defibrillator, angioplasty balloon, orthopedic device, spinalcage, implantable drug pump, artificial disc, ear disc).

The term “selective toxicity” refers to the property of differentiallytoxic effects on mammalian versus microbial cells. For example, aselectively toxic agent may effectively kill bacterial cells whilepermitting growth and viability of mammalian cells.

The term “toxic” refers to any detrimental or harmful effects on asubject, a cell, or a tissue as compared to the same cell or tissueprior to the administration of the toxicant.

As used herein, the terms “nanoparticle” and “nanoscale particles” areused interchangeably and refer to a nanoscale particle with a size thatis measured in nanometers, for example, a nanoscopic particle that hasat least one dimension of less than about 1000, 500, or 100 nm. Examplesof nanoparticles include nanobeads, nanofibers, nanohorns, nano-onions,nanorods, and nanoropes.

As used herein, the term “microparticle” and “microscale particles” areused interchangeably and refers to a microscale particle with a sizethat is measured in micrometers, for example, a microscale particle thathas at least one dimension of less than about 10 micrometers, 5micrometers, or 2 micrometers.

The term “wound dressing” refers to materials placed proximal to a woundthat have absorbent, adhesive, protective, osmoregulatory,pH-regulatory, or pressure-inducing properties. Wound dressings may bein direct or indirect contact with a wound. Wound dressings are notlimited by size or shape. Indeed, many wound dressing materials may becut or configured to conform to the dimensions of a wound. Examples ofwound dressing materials include but are not limited to gauze, adhesivetape, bandages, and commercially available wound dressings including butnot limited to adhesive bandages and pads from the Band-Aid® line ofwound dressings, adhesive bandages and pads from the Nexcare® line ofwound dressings, adhesive bandages and non-adhesive pads from theKendall Curity Tefla® line of wound dressings, adhesive bandages andpads from the Tegaderm® line of wound dressings, adhesive bandages andpads from the Steri-Strip® line of wound dressings, the COMFEEL® line ofwound dressings, adhesive bandages and pads, the Duoderm® line of wounddressings, adhesive bandages and pads, the TEGADERM™ line of wounddressings, adhesive bandages and pads, the OPSITE® line of wounddressings, adhesive bandages and pads, and biologic wound dressings. A“biologic wound dressing” is a type of wound dressing that comprises,e.g., is coated with or incorporates, cells and/or one or morebiomolecules or fragments of biomolecules that can be placed in contactwith the wound surface. The biomolecules may be provided in the form ofan artificial tissue matrix. Examples of such biomolecules include, butare not limited, to collagen, hyaluronic acid, glycosaminoglycans,laminin, vitronectin, fibronectin, keratin, antimicrobial polypeptidesand combinations thereof. Examples of suitable biologic wound dressingsinclude, but are not limited to, BIOBRANE™, Integra™, Apligraf®,Dermagraft®, Oasis®, Transcyte®, Cryoskin® and Myskin®.

As used herein, the term “antimicrobial silver composition” refers to acomposition that comprises silver as an active antimicrobial agent.Examples of “antimicrobial silver compositions” include, but are notlimited to silver nanoparticles, elemental silver, zero valent silver,multivalent silver ions carried by zirconium phosphate (ZP—Ag) (See,e.g., Wound Repair and Regeneration, 16: 800-804), and silver containingcompounds such as silver sulfadiazine and related compounds. The term“releasable antimicrobial silver composition” refers to a antimicrobialsilver composition that can be released from a material, for example, apolymer multilayer solid support, so that antimicrobial activity can beobserved. The release of the antimicrobial silver composition can bedefined as an amount of the composition released from a defined area orvolume of the material.

DETAILED DESCRIPTION OF THE INVENTION

The complex nature of wounds, and the lack of significant clinicalprogress based on current therapies, indicates the urgent need for newand unconventional approaches. The microenvironment of thepathologic/chronic wound bed is dysregulated with alterations inextracellular matrix constituents, degradative enzymes, growth factorand other cytoactive factor activity. The present invention providescompositions and methods for engineering of the wound bed itself by, forexample, altering the surface chemistry/structure of the wound bed topromote favorable cell behaviors that accelerate wound healing. In someembodiments, the wound bed is first treated with a priming agent (i.e.,primer) that provides a uniform, reactive bed on the wound surface. Theprimed wound bed is then treated with a desired agent, such a woundactive agent.

In normal wound healing, the coordinated interplay between fibroblasts,vascular cells, extracellular matrix components and epithelial cellsresults in a seamless progression through an inflammatory reaction,wound repair, contracture and coverage by an epithelial barrier.However, in many subjects with dysregulated wound microenvironment,systemic disease or other confounding circumstances, the wound healingprocesses become asynchronous resulting in an indolent ulcer (Pierce,2001, Am. J. Pathol. 159:399). In other subjects, a loss or lack ofregulatory responses to appropriately modulate cellular behaviors duringhealing causes an exuberant proliferative response that in itself is aproblem for the subject. This is particularly true for patients prone tokeloid formation or in burn patients where excessive fibroblasticproliferation and collagen production result in disfiguring anddisabling scar formation.

It is clear that across the spectrum of non-healing wounds that thereare a variety of inciting mechanisms and wound microenvironments. Thesewounds exhibit pathology at many junctures in the progression toclosure. Deficits in angiogenesis, fibroblastic responses andre-epithelialization all play a role in chronic wounds. Thus, a singlefactor treatment approach to chronic wounds is not likely to be fruitfulacross the disparate array of wounds presented in the clinical milieu.In such a heterogeneous environment, a more promising strategy involvesthe identification of compounds that are able to modulate specificaspects of the cellular response and behavior in the wound environment,providing the potential for custom crafting of a healing responsetailored to the individual wound and patient.

Due to the heterogeneous spectrum of wound environments, it iscontemplated that stimulating a “desirable” healing response is bestachieved by a differential modulation of the cellular responses withinthe wound. The present invention provides for the selection of a subsetof cytoactive compounds from a list of candidates for immobilizationinto the wound bed so as to differentially modulate the endothelial,fibroblastic and epithelial components within the healing response. Assuch, the present invention provides the potential to achieve highquality healing responses in a variety of clinical conditions, therebyproviding a strategy for engineering the wound bed for personalizedtherapeutics for each unique wound healing challenge encountered by aclinician. Specific examples where differential modulation of thecellular responses within the wound would yield substantial benefitinclude chronic wounds in diabetics or venous stasis ulcers, wherepancellular promotion of healing responses is desired but in particulara vibrant angiogenic response is needed to support all of the otheraspects of wound healing. In other wounds, where the strength of thehealed wound is a key concern, modulation to promote a fibroblasticresponse with a normal angiogenic and epithelial component is desirable.

In contrast, in some burns, such as deep second degree burns wheredermal and hair shaft epithelial elements persist to replace losttissues, a rich angiogenic and epithelial response is needed, but it isdesirable to mitigate the fibroblastic reaction to reduce scarhypertrophy, contracture and disfigurement. A similar mitigation isdesirable in healing subjects prone to keloid formation where theproliferative fibroblastic response in these wounds must be suppressed.It is also advantageous in wounds near joints or orifices to be able topromote rapid healing and coverage with epithelium but modulate thefibroblastic response so that improved suppleness of the tissue isretained. Modulation of the fibroblastic response in this way has thepotential to provide superior clinical outcomes and reduce the need forsubsequent reconstructive procedures targeted at recovery of limb orother critical bodily functions. The feasibility of such an approach hasbeen demonstrated previously, such as in the report by Muehlberger andcolleagues on the effects tretinoin on incisional wounds (Muehlberger etal., 2005, J. Am. Acad. Derm. 52:583). In that study, application oftretinoin resulted in an increased fibroblastic proliferation but theproduction of collagen was diminished.

The modification of surfaces has become an important challenge in thelast decade for applications in implant materials, prostheses, andartificial organs, allowing broad medical applications for implant andtissue engineering (Langer and Vacanti, 1993, Science 260:920); Peppasand Langer, 1994, Science 263:1715; Angelova and Hunkeler, 1999, TrendsBiotechnol. 17:409). For the improved integration efficiency ofimplants, several approaches, involving the alteration ofphysicochemical, morphological, and biochemical properties of devicesurfaces, have been investigated in an effort to obtain a suitablebone-implant interface. Self-assembled monolayers (SAMs) orLangmuir-Blodgett techniques have been commonly employed to produce newinterfaces (Mrksich, 1997, Curr. Opin. Colloid Interface Sci. 2:83;Lösche, 1997, Curr. Opin. Solid State Mater. Sci. 2:546).

More recently, a new versatile method of self assembled architecturesbased on the alternate deposition of polyanions and polycations has beendeveloped for the buildup of multilayered polyelectrolyte films (Decher,1997, Science 277:1232). Besides varying film thickness, roughness, andporosity, it is also possible to incorporate in the film architecturefunctionalized macromolecules (Caruso et al., 1997, Langmuir 13:3427;Cassier et al., 1998, Supramol. Sci. 5:309). It has also beendemonstrated that the layer-by-layer deposition process is not limitedin applicability to polyelectrolytes, but can be applied to viruses,nanoparticles, non-ionic polymers, proteins and other forms ofmicroscopic and nanoscopic matter. A recent review provides informationon a wide range of species and interfacial structures that can be formedby the layer-by-layer deposition procedure. The scope of the inventiondescribed herein is not limited to polyelectrolytes but applies to allspecies that have been demonstrated to be incorporated into interfacialstructures by the layer-by-layer deposition process.

The present invention provides a variety of embodiments for altering thecomposition of the wound bed. In some embodiments, a wound modifyingagent is applied to prime the wound bed. As described in detail below,wound modifying agents are agents that applied to a wound bed and eithercovalently or noncovalently modify the wound bed. Examples of woundmodifying agents include homobifunctional and heterobifunctionallinkers, polyelectrolytes, non-ionic polymers, combinations ofpolyelectroloytes and non-ionic polymers, and nano- and micro-particlesincluding beads and needles. In some embodiments, the wound modifyingagent alters a property of the wound bed selected from the groupconsisting of compliance, pH, alkalinity, and oxidative or reductivestrength, net charge, hydrophilicity, osmotic strength, nanoscale orsubmicron topographic features, electroconductivity, MMP production,phagocytosis, and transglutaminase activity. In preferred embodiments,the wound modifying agents are used to incorporate wound active agentsso that the wound active agents are localized to the wound bed. Thewound active agents can be covalently or noncovalently attached to thewound modifying agent. Furthermore, the wound active agents may form agradient via the wound modifying agent. In further embodiments, thewound modifying agents alter the compliance of the wound bed. In theseembodiments, the polymers or nano- or micro-particles have apredetermined hardness. In further embodiments, the compliance gradientswith varying levels of hardness may be formed by the polymers, nano- ormicro-particles.

In some embodiments of the present invention, the wound active agent issilver or a form of silver. Silver is a widely used nonspecific biocidalagent that acts against a very broad spectrum of bacterial species (Yinet al., 1999, J. Burn Care Rehabil. 20:195; herein incorporated byreference in its entirety), yeast species, fungal species (Wright etal., 1999, Am. J Infect. Control 27:344; herein incorporated byreference in its entirety), and viruses (Hussain et al., 1991, Biochem.Biophys. Res. Comm. 189:1444; herein incorporated by reference in itsentirety), including several antibiotic resistant strains (Wright etal., 1998, Am. J. Infect. Control 26:572; herein incorporated byreference in its entirety). However, topical silver agents undergo fastinactivation in the wounds because of the highly reactive nature ofsilver ions. Frequent wound dressings result in large excess of silverbeing delivered to the wound, resulting in toxic effects from overdose.In vitro studies have shown cytotoxic effects of silver ions onfibroblasts (Poon et al., 2004, Burns 30:140; Hildago et al., SkinPharmacol. Appl. Skin Physiol. 11:140; each herein incorporated byreference in its entirety), keratinocytes (Poon et al., 2004, Burns30:140; herein incorporated by reference in its entirety), hepatocytes(Baldi et al., 1988, Toxicol. Lett. 41:261; herein incorporated byreference in its entirety), and lymphocytes (Hussain et al., 1991,Biochem. Biophys. Res. Comm. 189:1444; herein incorporated by referencein its entirety).

The highly reactive nature of silver ions complicates their delivery towound bed. The released silver ions become rapidly inactive as theyreadily bind to proteins and chloride within complex wound fluid (Mooneyet al., 2006, Plastic and Reconstr. Surg. 117:666; herein incorporatedby reference in its entirety), resulting in unwanted adsorption ofsilver ions in epidermis cells and sweat glands (Klasen, 2000, Burns26:117; herein incorporated by reference in its entirety). Silver basedtopical solutions like 0.5% silver nitrate, or ointments like 1% silversulfadiazine cream, that are currently used in clinics for woundhealing, release silver at concentrations up to 3200 ppm but most ofthis is rapidly inactivated though the formation of chemical complexesin the wound (Dunn et al., Burns, 2004, 30(supplement 1):S1; hereinincorporated by reference in its entirety), necessitating frequentapplications, up to 12 times a day for silver nitrate solutions and atleast twice a day with silver sulfadiazine creams. Frequent dressingsresult in large excess of silver being delivered to the wound, resultingin toxic effects and discoloration from overdose (Atiyeh et al., 2007,Burns 33:139; Trop et al., 2006, J. Trauma 60:648; each hereinincorporated by reference in its entirety). Wound-dressings with silverincorporated into the dressing itself have been recently introduced.They provide prolonged release of silver to the wound, allowingdressings to be changed less frequently. However, thesereservoir-dressings have to be impregnated with large amount of silver,which results in cytotoxicity. Silver released from a leading commercialwound-dressing Acticoat™, that contains nanocrystalline silver (Dunn etal., Burns, 2004, 30(supplement 1):51; herein incorporated by referencein its entirety), was shown to be toxic to in vitro monolayer cellcultures of keratinocytes and fibroblasts (Poon et al., 2004, Burns30:140; Trop et al., 2006, J. Trauma 60:648; each herein incorporated byreference in its entirety). Thus, the challenges with current topicalsilver antimicrobials lie in their low silver release levels, the lackof penetration, the rapid consumption of silver ions, and the presenceof silver nitrate or cream bases that are pro-inflammatory, negativelyaffecting wound healing. Issues like wound staining, electrolyteimbalance, and patient discomfort also exist.

In certain embodiments, the present invention comprises novel methodsfor providing controlled and localized loadings of non-cytotoxic levelsof antimicrobial silver compositions to surfaces that circumvents usingexcess-loading of silver in the wound while retaining anti-bacterialactivity and reduced cytotoxicity. In experiments conducted during thecourse of developing certain embodiments of the present invention(Example 13), nanometer-thick polymeric films were assembled that wereimpregnated with silver nanoparticles to levels resulting in efficientkilling of bacteria but no cytotoxic effects on the adherence and growthof mouse fibroblasts cells on the films. In some embodiments, thepolymeric films are impregnated with an antimicrobial silver compositionby incubating the film in an antimicrobial silver composition asdescribed in Example 13. In other embodiments, the antimicrobial silvercomposition is directly incorporated into the polymer multilayer duringsynthesis of the multilayer. See, e.g., Langmuir. 2005 Dec. 6;21(25):11915-21.

The silver-nanoparticles impregnated thin films of some embodiments ofthe present invention exploit different principles for delivering silverinto the wound-matrix. The films can be applied directly on the exposedwound-bed, allowing them to release the silver ions locally into thewound. This reduces the amount of bactericidal silver needed toimpregnate into the film by several orders compared to topical silverdelivery agents, significantly reducing the silver-based toxicity. Whilethe present invention is not limited to any particular mechanism, and anunderstanding of the mechanism is not necessary to practice the presentinvention, it is contemplated that while silver-impregnated dressingsand ointments have to deliver high levels of silver into the wound bedto overcome rapid consumption of silver ions in wound-fluid that limitsthe penetration of released silver, the localized release of silverright into the wound-matrix by some polymeric thin film embodimentspresented herein circumvents the use of large loadings of silver.

Some molecularly-thin composite film embodiments of the presentinvention can be tuned to contain as low as 0.4 μg/cm² of soluble silverand release a total of less than 1 ppm silver ions in buffers. Suchfilms display 99.9999% bacteria-killing efficiency without anymeasurable cytotoxicity to mammalian cells. Furthermore, filmscontaining these levels of silver allow adherence and growth ofmammalian cells (e.g., NIH-3T3 mouse fibroblasts). In some embodiments,the releasable antimicrobial silver composition is loaded at an amountof from 1 or 10 to about 50, 100, 200, 300, 400, 500 or 1000 μg/cm² ofthe polymer multilayer and/or releasable in an amount of about 0.01 and100 μg/cm² of the polymer multilayer per day. In some embodiments, thereleasable antimicrobial silver composition is releasable in an amountof about 0.05 and 100 μg/cm² of the polymer multilayer. In someembodiments, the releasable antimicrobial silver composition isreleasable in an amount of about 0.05 and 20 μg/cm² of the polymermultilayer. In some embodiments, the releasable antimicrobial silvercomposition is releasable in an amount of about 0.05 and 5 μg/cm² of thepolymer multilayer. In some embodiments, the releasable antimicrobialsilver composition is releasable in an amount of about 0.05 and 2 μg/cm²of the polymer multilayer. In some embodiments, the releasableantimicrobial silver composition is releasable in an amount of about0.05 and 1 μg/cm² of the polymer multilayer. In some embodiments, thereleasable antimicrobial silver composition is releasable in an amountof about 0.1 to 0.5 μg/cm² of the polymer multilayer.

Experiments conducted during the course of developing some embodimentsof the present invention allowed systematic variation of theconcentration of silver in the films and demonstrated their cytotoxicityand anti-bacterial efficiency to be dependent on the silver-loading. Incomparison, the amount of soluble silver in the commercial wounddressing Acticoat™ is ˜100 μg/cm² (Dunn et al., 2004, Burns30(supplement 1):S1; herein incorporated by reference in its entirety).Acticoat™ releases a total of over 120 ppm silver on dissolution inwater for 24 hr (Taylor et al., 2005, Biomaterials 26:7221; hereinincorporated by reference in its entirety), and has been shown to becytotoxic to keratinocytes and fibroblasts (Poon et al., 2005, Burns30:140; Trop et al., 2006, J. Trauma 60:648; each herein incorporated byreference in its entirety).

Several reports exist on composite films of polyelectrolytes thatincorporate silver and display anti-bacterial activity by releasingsilver in the solution (Lee et al., 2005, Langmuir 21:9651; Li et al.,2006, Langmuir 22:9820; Grunlan et al., 2005, Biomacromolecules 6:1149;Yu et al., 2007, Bioconj. Chem. 18:1521; Shi et al., 2006, J. Biomed.Mat. Res. Part A 76A:826; each herein incorporated by reference in itsentirety). However, all these studies have focused on controlling thevolume fraction and concentration of silver in the films. Only filmscontaining high loadings of silver (˜5.5 μg/cm² or more) have been shownto demonstrate anti-bacterial activity (Wang et al., 2002, Langmuir18:3370; Logar et al., 2007, Nanotechnol. 18:325601; each hereinincorporated by reference in its entirety). Such polyelectrolyte films,when loaded with those levels of silver, display strong cytotoxicity andkill 100% NIH-3T3 cells seeded on them (e.g., Example 13).

In experiments conducted during the course of developing certainembodiments of the present invention (e.g., Example 13), loading levelsof silver in PEMS were identified and achieved that lead tosilver-impregnated antibacterial molecularly-thin films permittingadhesion of mammalian cells without exhibiting cytotoxicity. The filmsfind use for the localized delivery of bactericidal silver to thewounds, reducing risks of toxicity from silver overdose observed withother topical delivery agents. In some embodiments, implantable medicaldevices can be coated with these silver-impregnated thin films to killbacteria right during their initial attachment to these surfaces andprevent bacterial colonization, a leading cause of implant failure.

Thus, the silver-releasing moleculary-thin composite films of someembodiments of the present invention have advantage over: 1) othertopical delivery agents of silver currently used in clinics; 2)wound-dressings that contain large amounts of silver in them; and 3)other bactericidal composite thin-films containing large amounts ofsilver, which are cytotoxic to mammalian cells and do not allowmammalian cells to adhere and grow over them.

Using silver-nanoparticle molecularly-thin films for localized deliveryof bactericidal silver in wounds can overcome silver-related toxicityencountered with topical silver-delivery agents for wound healing (Poonet al., 2004, Burns 30:140; Baldi et al., 1988, Toxicol. Lett. 41:261;Atiyeh et al., 2007, Burns 33:139; Coombs et al., 1992, Burns 18:179;each herein incorporated by reference in its entirety). Furthermore,these polyelectrolyte multilayers (PEMs) are uniform, highlyinterpenetrated ultrathin nanocomposite films, typically far less than 1μm thick (Decher, 1997, Science 277:1232; Hammond, 1999, Curr. Opin.Colloid Interface Sci. 4:430; each herein incorporated by reference inits entirety). Their porous and supramolecular architecture allowsincorporating a variety of molecules including DNA, enzymes, viruses,dendrimers, colloids, inorganic particles, and dyes (Decher, 1997,Science 277:1232; herein incorporated by reference in its entirety).Thus, along with delivering bactericidal silver, in some embodimentsthey can be used for simultaneous localized delivery of other bioactiveagents in the wound-matrix (e.g., cell recruiting growth factors, DNAplasmids encoding such growth factors). Since PEMs can conformally coatsubstrates of any type, size or shape, including natural and syntheticpolymers (Hammond, 1999, Curr. Opin. Colloid Interface Sci. 4:430;herein incorporated by reference in its entirety), they can beconstructed on any wound-bed or implantable medical device.

In one embodiment, the present invention provides for the deposition andimmobilization of cytoactive factors and extracellular matrices (ECMs)on the wound bed by using, for example, polyelectrolyte multilayers orbeads. FIG. 1 provides a schematic diagram 100 of a wound bed 110 onwhich a polyelectrolyte multilayer 130 has been deposited. The diagram100 depicts that the wound bed 110 comprises a heterogeneous surfacedepicted by shapes 120 which represent different chemical moieties. Thepolyelectrolyte multilayer 130 provides a homogenous surface onto whichfunctional groups can 140 can be attached to form a homogenousfunctionalized surface 150. In the embodiment depicted, the functionalgroups are uniform, however, in some preferred embodiments, differentfunctional groups are utilized. A wide variety of active agents can thenbe attached to the surface via the functional groups 140. In otherembodiments, the wound bed is covalently modified with covalentmodification agents. The covalent modification agents include, but arenot limited to, homobifunctional and heterobifunctional cross-linkers aswell as photoactivatable cross linkers. FIG. 2 provides a schematicdiagram 200 of a wound bed 210 comprising a heterogeneous surfacedepicted by shapes 220 which represent different chemical moieties. Thewound bed is covalently modified by reacting covalent modificationagents 230 with the different chemical moieties to provide a relativelyhomogenous functionalized surface 250. In preferred embodiments,covalent modification agents 230 present functional groups 240. In theembodiment depicted, the functional groups are uniform, however, in somepreferred embodiments, different functional groups are utilized. A widevariety of active agents can then be attached to the surface via thefunctional groups 240. These embodiments are discussed in more detailbelow.

It is contemplated that the wound bed is an extremely heterogeneousenvironment. The compositions and methods of the present invention aredesigned to modify the wound bed to provide a homogenous environmentthat provides for uniform and predictable delivery or uniformincorporation of active agents into the wound bed. Surprisingly, it hasbeen found that modification of wound beds in this manner greatlyreduces the amount of active agent which is needed; i.e., the effectiveamount of active agent needed is reduced. Surface functionalizationallows for precise control of the amount of active agent used ordelivered and further allows for the formation of gradients of activeagents on the wound bed. In some preferred embodiments, the primingagent is optimized to react with the wound bed. In some embodiments, thepriming agent provides an optimized surface for enhanced or optimizeddelivery of an active agent. In some embodiments, a chemical parameterof the wound bed is changed. For example, the wound bed may be modifiedto be more or less acidic, basic, alkaline, reducing, or oxidizing orhave a higher or lower ionic strength.

There is a wide array of candidate molecules for improving healingchronic wounds. For example, basement membrane constituents and growthfactors promote wound healing. In some embodiments, the extracellularmatrices deposited and immobilized are constituents of native basementmembrane. Native ECMs comprise a mixture of glycoproteins, proteoglycansand hyaluronic acid. These glycoproteins and proteoglycans include, butare not limited to, fibrin, elastin, fibronectin, laminins,glycosaminoglycans, nidogens and collagens. Cytoactive factors such asgrowth factors are also part of ECMs. In some embodiments, extracellularmatrix components, such as collagen, laminin, glycosaminoglycans, orhyaluronic acid are deposited and immobilized on a wound bed. In someembodiments, a synthetic matrix such as MATRIGEL™ is deposited on awound bed. MATRIGEL™ is a commercially available basement membrane likecomplex that retains many characteristics of a native basement membrane,including a three-dimensional nanoscale topographic surface. The presentinvention is not limited to a particular mechanism. Indeed, anunderstanding of the mechanism is not necessary to practice the presentinvention. Nonetheless, it is contemplated that the nanoscaletopographic features of a basement membrane modulate fundamental cellbehaviors including migration, adhesion, proliferation anddifferentiation (Abrams et al., 2002, Biomimetic Materials and Design:Interactive Biointerfacial, Tissue Engineering, and Drug Delivery, Eds.Dillow and Lowman; Diehl et al., 2005, J. Biomed. Mater. Res. A 75:603;Foley et al., 2005, Biomaterials 26:3639; Karuri et al., 2004, J. CellSci. 117:3153; Liliensiek et al., 2006, J. Biomed. Mater. Res. A79:185). In some embodiments, the present invention further providesmethods, formulations, compositions and kits for altering the complianceof the wound surface. In some embodiments, the local compliance (thecompliance that cells see) is altered by immobilizing a thin layer ofextracellular matrix constituents such as MATRIGEL™ or an appropriatehydrogel or other synthetic matrix or by enzymatic treatment of thewound bed. In other embodiments, compliance is altered by the additionof cross-linking agents to the wound bed to cross-link componentsalready presenting the wound bed, or components deliberately introducedinto the wound bed. It has also been demonstrated by Picart andcoworkers that it is possible to control the compliance of multilayerstructures formed from polyelectrolytes by the addition of cross-linkingagents.

In some embodiments, the cytoactive factors that are deposited andimmobilized on a wound bed include, but are not limited to, thosefactors that are mitogenic for epithelial cells and vascular endothelialcells and other factors that are elements in wound closure. For example,in some embodiments, growth factors such as platelet derived growthfactor (PDGF), and/or epidermal growth factor (EGF), known to bemitogenic for epithelial cells are deposited in a wound bed. In otherembodiments, vascular endothelial growth factor (VEGF), known to bemitogenic for vascular endothelial cells, comprise the cytoactivefactors immobilized on the wound bed. It is contemplated that thepresent invention is not limited by the ECM components or cytoactivefactors immobilized on the wound bed, indeed any extracellular matrixcomponents and/or cytoactive factor that improves wound healing isequally applicable. Additional cytoactive and wound active agents thatcan be incorporated are provided below.

I. Priming the Wound Bed

In some embodiments, the present invention provides compositions andmethods for priming the wound bed to provide uniform reactive surfacefor later modification. Suitable compositions for priming a wound bedinclude, but are not limited to, polyelectrolytes and chemicalcrosslinking agents that react covalently with functional groups foundin wound beds such as carboxy, thiol, amide and sugar groups.

A. Multilayer Deposition on Wound Bed

In some embodiments, the present invention provides compositions,formulations, methods and kits for depositing a multilayer structure ona wound bed. In some embodiments, the multilayer structures compriselayers of polymers that form polyelectrolytes, while in otherembodiments, the multilayers comprise polymers that do not have a charge(i.e., non-ionic polymers) or a combination of charged and unchargedpolymer layers. In some embodiments, it is contemplated thatpolyelectrolyte films built-up by the alternated adsorption of cationicand anionic polyelectrolyte layers constitute a novel and promisingtechnique to modify wound surfaces in a controlled way [(Decher et al.,1992, Thin Solid Films 210/211:831; Decher, 1997, Science 277:1232). Oneof the most important properties of such multilayers is that theyexhibit an excess of alternatively positive and negative charges (Carusoet al., 1999, J Am Chem Soc 121:6039; Ladam et al., 2000, Langmuir16:1249). Not only can this constitute the motor of their buildup(Joanny, 1999, Eur. Phys. J. Biol. 9:117), but it allows, by simplecontact, to adsorb a great variety of compounds such as dyes,particles(Cassagneau et al., 1998, J. Am. Chem. Soc. 120:7848; Caruso etal., 1999, Langmuir 15:8276; Lvov et al., 1997, Langmuir 13:6195), claymicroplates (Ariga et al., 1999, Appl. Clay Sci. 15:137) and proteins(Keller et al., 1994, J. Am. Chem. Soc. 116:8817; Lvov et al., 1995, J.Am. Chem. Soc. 117:6117; Caruso et al., 1997, Langmuir 13:3427).

In some embodiments, the polymer multilayers, such as polyelectrolytemultilayers, are nanoscale in dimension. Accordingly, in someembodiments, the polymer multilayers are from about 1 nm to 1000 nmthick, from about 1 nm to 500 nm thick, from about 1 nm to 100 nm thick,from about 1 nm to about 25 nm thick, from about 1 nm to about 10 nmthick, or less than about 500 nm, 100 nm, 25 nm or 10 nm thick. It iscontemplated that the nanoscale dimension of the polymer multilayers(i.e., the nanoscale thickness) allows for the loading of a lower totalamount of an active agent while still allowing delivery of an effectiveamount (i.e., an amount of active agent that accelerates wound healingas compared to controls) of the active agent as compared to matrixstructures with greater thickness. It is contemplated that the lowertotal loading levels result in reduced toxicity in the woundenvironment, especially when antimicrobial compounds are incorporatedinto the polymer multilayer.

In some embodiments, the compliance of the polymer multilayers isadjusted to facilitate cell migration in the wound. In some embodiments,the polymer multilayers exhibit a compliance, measured in kilopascals(kPa) of from about 3 to about 500 kPa, about 7 to about 250 kPa, about10 to about 250 kPA or from about 10 to about 200 kPa.

1. Formation of Polyelectrolyte Layers

The cationic polyelectrolyte poly(L-lysine) (PLL) interacts with anionicsites on cell surfaces and in the extracellular matrix (Elbert andHubbell, 1998, J. Biomed. Mater. Res. 42:55). In some embodiments, thepresent invention provides a method of treating a wound with thesequential application of a cationic polyelectrolyte, an anionicpolyelectrolyte, and a wound active agent to the wound. In otherembodiments, the treatment includes the sequential and repeatedapplication of a cationic polyelectrolyte, an anionic polyelectrolyte,and a wound active agent to the wound.

Polyelectrolyte layers are formed by alternating applications of anionicpolyelectrolytes and cationic polyelectrolytes to surfaces to form apolyelectrolyte layer. The layers can be used to deliver a wound activeagent to a wound. Preferably, at least four layers, and, morepreferably, at least six layers are used to form the polyelectrolytemultilayer.

The method of treatment of the present invention is not limited to useon a wound surface. The formation of a polyelectrolyte layer thatincludes a wound active agent may be formed on any surface to whichdelivery of a wound active agent is desirable.

In some embodiments, the cationic polyelectrolyte used is PLL and theanionic polyelectrolyte used is poly(L-glutamic acid) (PGA). Indeed, theuse of a variety of polyelectrolytes is contemplated, including, but notlimited to, poly(ethylene imine) (PEI), poly(allylamine hydrochloride)(PAH), poly(sodium 4-styrenesulfonate) (PSS), poly(acrylic acid) (PAC),poly(maleic acid-co-propylene) (PMA-P), poly(acrylic acid) (PAA), andpoly(vinyl sulfate) (PVS). It is also possible to use naturallyoccurring polyelectrolytes, including hyaluronic acid and chondroitinsulfate.

In still further embodiments, the polymer is a dendrimer, graftedpolymer, or star architecture polymer. In other embodiments, themultilayer responds to or is organized in the presence of an electricfield, for example an electric field formed by placing electrodes oneither side of a wound.

Referring to FIG. 1, in some embodiments, the polymer multilayer 130 canbe comprised of polystyrene sulfonate, an amphiphillic polyelectrolytewith an affinity for hydrophobic regions of the wound bed, and anamphoteric polymer. The polymer multilayer is preferably functionalizedwith one or more crosslinking agents presenting an alkyne so that auniform surface is presented (e.g., 140 in FIG. 1 where x represents analkyne group). From this point, widely available click chemistries canbe used to add desired wound active agents to the modified surface ofthe wound. In some embodiments, the wound modifying agent is an azideconjugate or otherwise comprises an azide group and is reacted with thealkyne groups displayed on the wound bed in a Huisgen Cycloaddition.

Other suitable methods for preparing polyelectrolyte multilayers includethose described, for example, in Cho and Char, Langmuir 20:4011-4016,2004; Okamura et al., Adv. Mater. 21, 4388-92 (2009), Cho et al., Adv.Mat. 13(14):1076-1078 (2001); and U.S. pat. Publ. 2010/0062258; theentire contents of each of which is incorporated herein by reference.Suitable methods include layer by layer deposition, formation on SAMs,and spin coating assisted assembly.

2. Cationic Polymers

Cationic polymers useful in the present invention can be anybiocompatible water-soluble polycationic polymer, for example, anypolymer having protonated heterocycles attached as pendant groups. Asused herein, “water soluble” means that the entire polymer must besoluble in aqueous solutions, such as buffered saline or buffered salinewith small amounts of added organic solvents as co-solvents, at atemperature between 20 and 37° Centigrade. In some embodiments, thematerial will not be sufficiently soluble (defined herein as soluble tothe extent of at least one gram per liter) in aqueous solutions per sebut can be brought into solution by grafting the polycationic polymerwith water-soluble polynonionic materials such as polyethylene glycol.

Representative cationic polymers include natural and unnatural polyaminoacids having net positive charge at neutral pH, positively chargedpolysaccharides, and positively charged synthetic polymers. Examples ofsuitable polycationic materials include polyamines having amine groupson either the polymer backbone or the polymer side chains, such aspoly-L-lysine (PLL) and other positively charged polyamino acids ofnatural or synthetic amino acids or mixtures of amino acids, including,but not limited to, poly(D-lysine), poly(ornithine), poly(arginine), andpoly(histidine), and nonpeptide polyamines such as poly(aminostyrene),poly(aminoacrylate), poly(N-methyl aminoacrylate),poly(N-ethylaminoacrylate), poly(N,N-dimethyl aminoacrylate),poly(N,N-diethylaminoacrylate), poly(aminomethacrylate), poly(N-methylamino-methacrylate), poly(N-ethyl aminomethacrylate), poly(N,N-dimethylaminomethacrylate), poly(N,N-diethyl aminomethacrylate),poly(ethyleneimine), polymers of quaternary amines, such aspoly(N,N,N-trimethylaminoacrylate chloride),poly(methyacrylamidopropyltrimethyl ammonium chloride), and natural orsynthetic polysaccharides such as chitosan. In some embodiments, PLL isa preferred material.

In general, the polymers must include at least five charges, and themolecular weight of the polycationic material must be sufficient toyield the desired degree of binding to a tissue or other surface, havinga molecular weight of at least 1000 g/mole.

3. Anionic Polymers

Polyanionic materials useful in the present invention can be anybiocompatible water-soluble polyanionic polymer, for example, anypolymer having carboxylic acid groups attached as pendant groups.Suitable materials include alginate, carrageenan, furcellaran, pectin,xanthan, hyaluronic acid, heparin, heparan sulfate, chondroitin sulfate,dermatan sulfate, dextran sulfate, poly(meth)acrylic acid, oxidizedcellulose, carboxymethyl cellulose and crosmarmelose, synthetic polymersand copolymers containing pendant carboxyl groups, such as thosecontaining maleic acid or fumaric acid in the backbone. Polyaminoacidsof predominantly negative charge are also suitable. Examples of thesematerials include polyaspartic acid, polyglutamic acid, and copolymersthereof with other natural and unnatural amino acids. Polyphenolicmaterials such as tannins and lignins can be used if they aresufficiently biocompatible. Preferred materials include alginate,pectin, carboxymethyl cellulose, heparin and hyaluronic acid.

4. Nonionic Polymers

In some embodiments, the multilayer structures are formed from unchargedpolymers or from a combination of charged and uncharged polymers.Examples of uncharged polymers include, but are not limited to, dextran,dextran sulfate, diethylaminoethyl (DEAE)-dextran, hydroxyethylcellulose, ethyl(hydroxyethyl) cellulose, acrylamide, polyethyleneoxide, polypropylene oxide, polyethylene oxide-polypropylene oxidecopolymers, PAAN_(a), Ficoll, polyvinylpyrolidine, and polyacrylic acid.

5. Amphoteric Polymers

In some embodiments, the multilayer structures are formed from one ormore amphoteric polymers, alone in combination with the other polymersdescribed herein. In some embodiments, the amphoteric polymers compriseone or more of acrylic acid (AA), DMAEMA (dimethylaminoethylmethacrylate), APA (2-aminopropyl acrylate), MorphEMA (morpholinoethylmethacrylate), DEAEMA (diethylaminoethyl methacrylate), t-ButylAEMA(t-butylaminoethyl methacrylate), PipEMA (piperidinoethyl methacrylate),AEMA (aminoethyl methacrylate), HEMA (2-hydroxyethyl methacrylate), MA(methyl acrylate), MAA (methacrylic acid) APMA (2-aminopropylmethacrylate), AEA (aminoethyl acrylate). In some embodiments, theamphoteric polymer comprises (a) carboxylic acid, (b) primary amine, and(c) secondary and/or tertiary amine. The amphoteric polymers have anisoelectric point of 4 to 8, preferably 5 to 7 and have a number averagemolecular weight in the range of 10,000 to 150,000.

6. Application of Multilayers

The wound modifying agent, such as a polymer multilayer, can be appliedto the wound by a variety of methods. In some embodiments, it iscontemplated that the polymer or polymer multilayers, is applied,preferably sequentially, to the wound using either a pump (includingsyringes, ink jet printers, and electrojets) or aerosol spray. In otherembodiments, particle bombardment is utilized. In other embodiments, theuse of a brush including an air brush is contemplated. In otherembodiments, a sponge is utilized. In other embodiments a solid supportor stamp such as an elastomeric material, for example, PDMS(polydimethylsiloxane), silicone, hydrogel or latex, is used to supportthe wound modifying agents and mechanically transfer the agent into thewound bed. In these embodiments, the polymer multilayers are pre-formedon the stamp. In further embodiments, nano- or micro-particles arearranged on the stamp for delivery to the wound. In other approaches,electric fields or magnetic fields are used to facilitate transfer ofthe wound modifying agents into the wound bed.

In some embodiments, the polymers are applied to a wound by a spray,such as via a pump or aerosol device. In some embodiments, the polymerlayers are applied sequentially. In one embodiment, a solution,dispersion, or suspension of the wound modifying agent and wound activeagent is sprayed onto the wound to form the polyelectrolyte layer. Inembodiments where the wound modifying agent and wound active agent aresupplied as aerosols, a propellant is used to provide the force forexpulsion from the container. In some embodiments, the wound modifyingagent or the wound active agent and the propellant form a single liquidphase so that the composition is delivered consistently.

In general, for aerosol delivery, the ingredients of the composition aremixed to form a substantially homogenous solution, slurry, dispersion,or the like. For two-part systems, each part is mixed. The compositionsare placed in an appropriate container and the propellant is added usingconventional techniques, such as cold filling or pressure fillingtechniques. The composition can be delivered using a commerciallyavailable aerosol sprayer such as, for example, the Preval™ aerosolspray unit available from Precision Valve Corporation, NY, USA, whichhas a modular power unit and refillable container jar. The propellant isa mixture of propane, isobutane, and dimethyl ether.

The composition can also be delivered using a syringe outfitted with aspray head, or a dual spray device outfitted with a spray head and,optionally, a mixing chamber. The device may include a meter so that thequantity of applied composition can be controlled.

Any of a number of propellants known to those skilled in the art can beused, provided that it is chemically inert to the other ingredients ofthe composition. Suitable propellants include vinyl chloride andmixtures of vinyl chloride and dichlorodifluoromethane, otherfluorochlorohydrocarbons known as the Freons and the Genetrons, andblends of fluorochlorohydrocarbons, chlorinated hydrocarbons, andhydrocarbons. Examples of fluorochlorohydrocarbons includetrichloromonofluoromethane, dichlorodifluoromethane,dichloromonofluoromethane, 2-tetrafluoroethane,1,1-dichloro-1,2,2-tetraf-luoroethane, 1-chloro-1,1-difluoroethane,1,1-difluoroethane, and octofluorocyclobutane, and mixtures thereofExamples of hydrocarbons include liquefied petroleum gases like propane,isobutane, and N-butane and mixtures thereof. Dimethyl ether is anotherpropellant. Compressed gas propellants that are preferably non-toxic,non-flammable, and inert can be used. Examples include carbon dioxide,nitrous oxide and N₂ and the like. Mixtures of the above are often used.

The quantity of propellant used is critical only in that if aninsufficient amount is used, the driving force to expel the entirecomposition from the container will be lacking Generally, thecomposition will comprise from 75% to 95% by weight propellant.

In some embodiments, the invention contemplates a kit comprising acontainer with a cationic polyelectrolyte, a second container containingan anionic polyelectrolyte, and a third container containing at leastone wound active agent. In still other embodiments, in addition to acontainer with a cationic polyelectrolyte, a second container containingan anionic polyelectrolyte, and a third container containing at leastone wound active agent, the kit provides an application device foradministering the polyelectrolytes and at least one wound active agentto the wound. In some preferred embodiments, the containers comprise apropellant. In other embodiments, the containers comprise a pump.

In some embodiments, contacting comprises delivery of the polymer andthe at least one wound active agent to the wound using a reactionchamber dressing (RCD). In some embodiments, it is contemplated that theRCD will comprise a solid barrier adhered to an area completelysurrounding the wound. Within the solid barrier reside inflow andoutflow orifices to which tubes from solution reservoirs can beconnected. The use of a variety of solid barriers is contemplated,including, but not limited to, Gortex, latex, Teflon, PVDF, plastic andrubber.

In some embodiments, the wound modification agents are applied to thewound by microfluidics printing, microstamping (U.S. Pat. Nos. 5,512,131and 5,731,152, both of which are incorporated by reference herein intheir entirety), or microcontact printing (PCT Publication WO 96/29629,incorporated by reference herein in its entirety). In other embodiments,the wound modifying agents are applied to the wound via a pulse jet suchas an inkjet printer. Examples of suitable inkjet printers forapplication of biological fluids include those described in U.S. Pat.No. 7,128,398, WO 95/25116 and WO 98/41531, each of which isincorporated by reference in its entirety. In other embodiments, thewound modifying agents are applied by a drop dispensers such as the tipof a pin or in an open capillary and, touch the pin or capillary to thesurface of the substrate. Such a procedure is described in U.S. Pat. No.5,807,522. When the fluid touches the surface, some of the fluid istransferred. In other embodiments, the wound modifying agents areapplied be pipetting, micro-pipetting or positive displacement pumpssuch as the Biodot equipment (available from Bio-Dot Inc., IrvineCalif., USA).

One or more wound active agents are preferably applied to the woundalong with the wound modification agent. In some embodiments, the woundactive agent is covalently attached to the wound modification agent. Inother embodiments, the wound active agent is incorporated into the woundmodifying agent, for example, by application during sequentialapplication of polymer layers in a polymer multilayer. In otherembodiments, the wound active agents are delivered by a microarrayer,pipette, positive displacement pump, inkjet printer, microneedle array,elastomeric stamp, gene gun, electrojet, or air brush as described abovein relation to the wound modifying agents.

B. Modification of Wound Beds with Biocompatible Particles

In some embodiments, the wound modifying agent is a nano- ormicro-particle. In some embodiments, nanometer to submicrometer sizedbiocompatible particles, such as spherical (e.g., beads) and/ornon-spherical (e.g., oblongs, needles, cubes, tetrahedral, mushroom-likestructures, haybale-like structures) particles or electrospun polymers,are applied (e.g., either directly or indirectly) to the wound bed,thereby creating a three-dimensional topographic wound bed. For example,application of biocompatible particles to a wound bed results in thecreation of knobs, ridges, spikes, undulations, and the like in thewound bed. Microbeads have a size generally ranging from about 1 toabout 500 micrometers, while nanobeads have a size generally rangingfrom about 1 to about 1000 nanometers. Microbeads may further comprisemicro- (i.e., from 1 to 100 micrometers) or nano-scale (0.1 to 1000nanometer) features on the surface of the bead. Nanobeads may furthercomprise nanoscale features (i.e., 0.1 to 500 nanometer features) on thesurface of the bead. In some embodiments, a wound active agent ispresent in the form of a bead or particle, such as silver nanoparticles.

In some embodiments, the biocompatible particles are biodegradable. Insome embodiments, the biocompatible particles are not biodegradable. Thebiocompatible particles, for example, are modified with surfacechemistry cross-linkers that allow attachment and immobilization ofwound active agents, extracellular matrix compounds, polyelectrolytes,etc. as described further herein. It is contemplated that theincorporation of modified biocompatible particles, for example,facilitates the presentation of ECM constituents that support epithelialcoverage of the wound, provides cytoactive factors for wound healing,and introduces topographic features that support cellular behaviors forpromoting wound healing. In some embodiments, the biocompatibleparticles are functionalized with mesoscopic cross-linkers to, forexample, broadly enable covalent chemistry in the wound bed. In someembodiments, cross-linkers are attached to negatively chargedbiocompatible particles. In some embodiments, the biocompatibleparticles comprise layers of multiple different constituents for woundhealing, or a single constituent for wound healing. For example,spherical particles such as beads placed in a wound bed comprise, orupon which are layered, one or more intermixed species ofpolyelectrolytes, ECM agents, proteins with hydrolysable bonds, proteinswith enzymatically cleavable bonds, and the like for wound healing aspreviously described. In some embodiments, antimicrobials, either aloneor in combination with other wound healing compositions, are alsoapplied to the biocompatible particles. Antimicrobials include, but arenot limited to, antibiotics, metal based antimicrobial compositionscomprising silver (e.g., ionic silver, elemental silver, silvernanoparticles), copper, selenium, triclosan-based antimicrobials,thiabendazole-based antimicrobials, isothiazolinone-basedantimicrobials, zinc-pyrithione-based antimicrobials, and/or10′-oxybisphenoxarsine-based antimicrobials (OBPA). The presentinvention is not limited by the type of antimicrobial used.

In some embodiments, the size of the biocompatible particles, such asbeads, are at least 1 nm, at least 5 nm, at least 10 nm, at least 20 nm,at least 50 nm, at least 100 nm, at least 200 nm, at least 300 nm, atleast 500 nm, or at least 800 nm in diameter. In some embodiments, beadsand other spherical and non-spherical particles contain their ownsurface topography. For example, the bead surface may compriseundulations, indentations, tunnels, holes, knobs, ridges, etc. Sphericalparticles, such as beads, may or may not be inert and may, for example,be magnetic. Magnetic beads comprise, for example, a magnetic core ormagnetic particles. Examples of different bead compositions are foundat, for example, U.S. Pat. Nos. 5,268,178, 6,458,858, 6,869,858, and5,834,121, each of which is incorporated herein by reference in itsentirety.

In some embodiments, biocompatible particles of the present inventionused for wound healing are coated with layers of polyelectrolytes, ECMcomponents, antimicrobials, proteins with hydrolysable bonds, proteinswith enzymatically cleavable bonds, etc. and other wound healingcompositions wherein the surface compliance of the beads is maintainedfor optimal wound healing. For example, the compliance of the layers forwound healing as deposited on the biocompatible particles arecontemplated to be of optimal stiffness (e.g., not too soft, not toohard) such that cells within the wound bed are capable of optimalanchorage and spreading. Engler et al. (2004, Biophys. J. 86:617-628)discusses substrate compliance for cell anchorage and spreading. In someembodiments, the biocompatible particles are layered withpolyelectrolytes, ECM components, antimicrobials, etc. wherein substratestiffness of at least 1 kPa, at least 5 kPa, at least 8 kPa, at least 10kPa, at least 20 kPa, at least 40 kPa, at least 60 kPa, at least 80 kPais realized as measured using the methods of Engler et al. (2004). Inpreferred embodiments, substrate compliance of the wound healingcompositions as applied to biocompatible particles is at least 8 kPa toabout 80 kPa or 100 kPa. It will be recognized that hardness withinthese limit are contemplated without specifically listing all suchhardnesses, for example, 10, 20, 30, 40, 50, 60, or 70 kPa limits asupper or lower ranges are all contemplated by the present invention. Insome embodiments, the ECM composition preferentially used in conjunctionwith polyelectrolytes, antimicrobials, and other wound healingcompositions is collagen.

In some embodiments, the layers as applied to a wound bed or to abiocompatible particle comprise gradients of wound healing compositions,for example, wound active agents. For example, the concentrations of thecompositions are layered in a wound bed or on a biocompatible particlein a gradient such that higher concentrations of a particularcomposition is greater proximal to the wound bed than distal to thewound bed in a vertical fashion. The converse, where concentrations ofcompositions is greater distal to the wound bed than proximal, is alsocontemplated. Concentration of compositions in a wound bed or on abiocompatible particle wherein a horizontal gradient is deposited isalso contemplated. Topographical gradients are also contemplated,wherein compositions are deposited such that the concentrations ofcompositions in a wound bed or on a biocompatible particle follow thetopography of the substrate, for example, a higher concentration ofcompositions is deposited in the valleys of undulations of an exemplarysubstrate compared to the peaks of the undulations. Likewise, thepresent invention contemplates that compliance gradients can be formedin the wound bed by controlled application of micro- or nano-beads ofvarying hardness. For example, beads having one, two, three, four ormore different hardnesses are applied to form a vertical gradient (i.e.,a depth gradient) on the wound or a horizontal gradient (i.e., agradient along the length or width of the wound), or a combination ofvertical and horizontal gradients. Horizontal and vertical gradients canalso be formed with beads functionalized with 1, 2, 3, 4 or moredifferent wound active agents. See Ichinose et al., Biomaterials. Volume27, Issue 18, June 2006, Pages 3343-3350; Stefonek et al., Immobilizedgradients of epidermal growth factor promote accelerated and directedkeratinocyte migration. Wound Repair and Regeneration (OnlineEarlyArticles). doi:10.1111/j.1524-475X.2007.00288.x; Kapur et al.,Immobilized concentration gradients of nerve growth factor guide neuriteoutgrowth. Journal of Biomedical Materials Research Part A. Volume 68A,Issue 2, Pages 235-243; DeLong et al., Covalently immobilized gradientsof bFGF on hydrogel scaffolds for directed cell migration. Biomaterials26 (2005) 3227-3234; Liu, et al., 2007 Sep. 25; 17892312 EndothelialCell Migration on Surface-Density Gradients of Fibronectin, VEGF, orBoth Proteins.

In some embodiments, wound healing compositions applied to the wound bedor biocompatible particles (e.g., beads, needles, etc.) are timereleased, such that wound healing compositions that are applied to thewound bed or biocompatible particles are released over a period of time,for example 3 hours, 5 hours, 10 hours, 1 day, several days, one week,several weeks, etc. thereby providing short and/or long term treatmentfor the wound bed.

In some embodiments, biocompatible particles used in wound bed healingapplications of the present invention are not, for example, spherical aspreviously described, but take on shapes such as oblongs, needles,mushroom-like structures, haybale-like structures, etc. In someembodiments, the biocompatible particle shape is preferably needles. Themanufacture of needles useful in embodiments of the present inventioncan be accomplished through microfabrication techniques, such as thosefound in, for example, McAllister et al., 2003, Proc. Natl. Acad. Sci.100:13755-13760. In some embodiments, biocompatible particles are coatedand/or layered with wound healing compositions, anti-microbials,proteins that are hydrolyzably cleavable, proteins that areenzymatically cleavable, antimicrobials, etc. as described herein. Insome embodiments, the coated and/or layered biocompatible particles areapplied to a wound bed by stamping, spraying, or other methods asdescribed herein.

In some embodiments, the layers of wound healing compositions asdescribed herein are deposited on a wound bed or on biocompatibleparticles by electrostatic bonding. In other compositions,non-electrostatic interactions are utilized, such as van der Waalsinteractions, metal ion-ligand coordination or hydrogen bonding. In someembodiments, the layers of wound healing compositions as describedherein are deposited by piezoelectric application, using methods andsystems as described in, for example, U.S. Pat. No. 6,368,079 andSumerel et al., 2006, Biotechnol. J. 1:976-987. In other embodiments,the wound healing compositions are directly or indirectly deposited intothe wound bed by using electrojetting technologies, includingelectroextrusion, and electrospraying and electrospinning In someembodiments, the layers deposited comprise one or more wound healingcompositions. In some embodiments, the layers are biocompatibleparticles (e.g. spherical beads, needles, and the like) intermixed withwound healing compositions. In other embodiments, layered deposition issequential. For example, sequential deposition of wound healingcompositions alone, or sequential deposition of wound healingcompositions followed by biocompatible particles, followed by woundhealing compositions, etc. The present invention is not limited by theconstituents that make up a layer of deposition on a biocompatibleparticle, and many permutations of wound healing compositions andbiocompatible particle layering would be apparent to a skilled artisan.

In some embodiments, the deposition of layers in the wound bed or on abiocompatible particle or other substrate to be added to a wound bed isaccomplished by “stamping”, also referred to as “contact printing”. Astamp substrate is any substrate that can be used to transfer one ormore than one entity or composition (e.g., polyelectrolytes, ECMcomponents, proteins with hydrolyzable or enzymatically cleavable bonds,etc.) that is (are) covalently or non-covalently bound to the surface ofthe stamp substrate to another surface. Examples of suitable stampsubstrates include, but are not limited to, polydimethylsiloxane (PDMS)and other elastomeric (e.g., pliable) materials. In some embodiments,different concentrations of the same wound healing composition arearrayed in different areas of the stamp substrate. In other embodiments,a variety of different compositions are arrayed on the stamp substratesurface. In some embodiments, multiple wound healing compositions inmultiple concentrations are arrayed on the stamp substrate surface. Thewound healing compositions are then introduced to the stamp substratesurface, which are in turn stamped into the wound bed or onto anothersubstrate for introduction into the wound bed (e.g., biocompatibleparticles).

In other embodiments, the biocompatible particles, for example needles,are coated and/or layered with wound healing compositions,anti-microbials, proteins that are hydrolyzably cleavable, proteins thatare enzymatically cleavable, etc., and applied to a pad which issubsequently applied to a wound. Pads include, but are not limited to,band-aids, gauze, surgical packings, and the like. In some embodiments,the pad is impregnated with wound healing compositions, anti-microbials,proteins that are hydrolyzably cleavable, proteins that areenzymatically cleavable, etc. In some embodiments, the biocompatibleparticles (e.g., covered and/or layered with wound healing compositions,anti-microbials, proteins that are hydrolyzably cleavable, proteins thatare enzymatically cleavable, etc.) are affixed in a detachable ornon-detachable manner to the pad prior to applying the pad to a wound.In some embodiments, when the pad is removed from the wound thebiocompatible particles are retained (e.g., not detached) on the pad,whereas in other embodiments when the pad is removed from the wound thenanostructures are retained (e.g., detached) in the wound bed. Forexample, a pad is impregnated with compositions as described and furtheraffixed with biocompatible particles that are themselves coated and/orlayered with compositions as described for wound healing. The pad withbiocompatible particles is applied to the wound and while the pad issuperficial to the wound bed, the biocompatible particles thereon reachdown in proximity with the wound bed as compared to the location of thepad. The pad releases (e.g., either over a short period of time or in atime-release manner) the impregnated wound healing compositions on ornear the surface of the wound whereas the affixed biocompatibleparticles release the coated and/or layered wound healing compositions(e.g., either over a short period of time or in a time-release manner)more proximal to the wound bed. Alternatively, a pad with affixedbiocompatible particles (both pad and nanostructures comprising woundhealing compositions as previously described) is first applied to awound bed. The pad is subsequently removed; however the detachablebiocompatible particles remain in the wound bed. The pad serves not onlyto deliver wound healing compositions to a wound bed, but further servesa purpose of delivering biocompatible particles, such as needles, into awound bed. The biocompatible particles left in the wound bed, forexample, continue releasing wound healing compositions to the wound bedfor further healing. In some embodiments, a new (e.g., second, third,fourth, etc.) pad comprising impregnated wound healing compositions aspreviously described is re-applied to the wound wherein resides thebiocompatible particles retained by the original application of thefirst pad/nanostructure. The application of the new pad, for example,serves not only to impart fresh wound healing compositions to a woundbut also serves to recoat the biocompatible particles with fresh wouldhealing compositions that are released (e.g., either over a short periodof time or in a time-release manner) proximal to the wound bed.

The present invention is not limited to a particular mechanism. Indeed,an understanding of the mechanism is not necessary to practice thepresent invention. Nonetheless, it is contemplated that the negativelycharged macromolecular species and beads do not readily pass across cellmembranes, and therefore serve as a non-toxic means of wound bedhealing. As well, the size of the beads used determines thenanostructure of the wound bed, thereby allowing for personalized woundbed healing therapies. FIG. 6 provides an exemplary embodiment of theuse of beads for wound bed healing. However, the present invention isnot limited by the size of bead, the reactive groups found on the beads(e.g., carboxylic acid groups, thiol groups, amine groups, etc.), thecross-linkers used, or the cytoactive factors and other wound healingcompositions that are associated with the beads. Indeed, a myriad ofcombinations of compounds (e.g., small molecule, peptides, proteins,drugs, etc) for wound healing is contemplated for use with beads appliedto a wound bed.

In some embodiments, the particles modulate a wound response followingan application of an electric or magnetic field to the wound bed.Accordingly, in some embodiments, the particles are charged ormagnetized so that the particles migrate or reorganize in an electric ormagnetic field. In other embodiments, the beads are dielectric so thatthe beads experience dielectrophoresis in an AC electrical field. Inother embodiments, the beads are magnetic and migrate and/or transmitmechanical forces when exposed to a magnetic field. In otherembodiments, the beads are charged so that mechanical forces are appliedto the wound bed when an electric field is applied, for example, byplacing electrodes on either side of a wound.

In some embodiments, the nano- or micro-beads are applied to the woundby microfluidics printing, microstamping (U.S. Pat. Nos. 5,512,131 and5,731,152, both of which are incorporated by reference herein in theirentirety), or microcontact printing (PCT Publication WO 96/29629,incorporated by reference herein in its entirety). In other embodiments,the nano- or micro-beads are applied to the wound via a pulse jet suchas an inkjet printer. Examples of suitable inkjet printers forapplication of biological fluids include those described in U.S. Pat.No. 7,128,398, WO 95/25116 and WO 98/41531, each of which isincorporated by reference in its entirety. In other embodiments, thenano- or micro-beads are applied by drop dispensers such as the tip of apin or in an open capillary tube and, touch the pin or capillary tube tothe surface of the substrate. Such a procedure is described in U.S. Pat.No. 5,807,522. When the fluid touches the surface, some of the fluid istransferred. In other embodiments, the wound modifying agents areapplied be pipetting, micro-pipetting or positive displacement pumpssuch as the Biodot equipment (available from Bio-Dot Inc., IrvineCalif., USA). In still other embodiments, the nano- or micro-beads areapplied to the wound via a microneedle array.

C. Modification with Covalent Modifiers

In some embodiments, the present invention provides for the covalentimmobilization of factors to the wound bed. In some preferredembodiments, the covalent modification occurs via homobifunctional orheterobifunctional linkers. In some embodiments, the covalent modifiersare used to directly modify the wound bed by covalently attaching thewound bed. In some embodiments, the covalent modifiers are used tocovalently attach 1, 2, 3, 4 or more different wound active agents tothe wound bed. In some embodiments, the covalent modifiers are used toestablish gradients of the 1, 2, 3, 4 or more different wound activeagents in a vertical or horizontal plane with respect to the wound. Insome embodiments, the covalent modifiers are used in conjunction withthe polymer layers or beads describes above. In some embodiments, thecovalent modifies are used to attach wound active agents to the polymerlayers or beads, while in other embodiments, the covalent modifies areused to cross link the polymers or beads.

In some embodiments, the present invention provides methods oftreatment, comprising providing a subject having a wound, at least onecovalent modification agent and at least one wound active agent, andcontacting the wound with the at least one covalent modification agentand the at least one wound active agent under conditions such that theat least one wound active agent is covalently attached to the wound. Insome embodiments, the subject is a human. In other embodiments, thesubject is a non-human vertebrate. In some embodiments, the at least onecovalent modification agent is a homobifunctional cross-linker. In otherembodiments, the at least one covalent modification agent is aheterobifunctional cross-linker. For example, in some embodiments, thehomobifunctional cross-linker is an N-hydroxysuccinimidyl ester (e.g.,including, but not limited to, disuccinimidyl ester,dithiobis(succinimidylpropionate),3,3′-dithiobis(sulfosuccinimidylpropionate), disuccinimidyl suberate,bis(sulfosuccinimidyl)suberate, disuccinimidyl tartarate,disulfosuccinimidyl tartarate,bis[2-(succinimidyloxycarbonyloxy)ethyl]sulfone,bis[2-(sulfosuccinimidooxycarbonyloxy)ethyl]sulfone, ethyleneglycolbis(succinimidylsuccinate), ethyleneglycolbis(sulfosuccinimidylsuccinate), disuccinimidyl glutarate, andN,N′-disuccinimidylcarbonate). In some embodiments, the homobifunctionalcross-linker is at a concentration between 1 nanomolar and 10millimolar. In some preferred embodiments, the homobifunctionalcross-linker is at a concentration between 10 micromolar and 1millimolar. In other embodiments, the at least one covalent modificationagent is a heterobifunctional cross-linker (e.g., including, but notlimited to, N-succinimidyl 3-(2-pyridyldithio)propionate, succinimidyl6-(3-[2-pyridyldithio]-propionamido)hexanoate, sulfosuccinimidyl6-(3′-[2-pyridyldithio]-propionamido)hexanoate,succinimidyloxycarbonyl-α-methyl-α-(2-pyridyldithio)toluene,sulfosuccinimidyl-6-[α-methyl-α-(2-pyridyldithio)toluamido]hexanoate,succinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate,sulfosuccinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate,m-maleimidobenzoyl-N-hydroxysuccinimide ester,m-maleimidobenzoyl-N-hydroxy-sulfosuccinimide ester,N-succinimidyl(4-iodoacetyl)aminobenzoate,sulfo-succinimidyl(4-iodoacetyl)aminobenzoate,succinimidyl-4-(p-maleimidophenyl)butyrate,sulfosuccinimidyl-4-(p-maleimidophenyl)butyrate,N-(γ-maleimidobutyryloxy)succinimide ester,N-(γ-maleimidobutyryloxy)sulfosuccinimide ester, succinimidyl6-((iodoacetyl)amino)hexanoate, succinimidyl6-(((6(4-iodoacetyl)amino)hexanoyl)amino)hexanoate, succinimidyl4-(((iodoacetyl)amino)methyl)cyclohexane-1-carboxylate, succinimidyl6-((((4-iodoacetyl)amino)methyl)cyclohexane-1-carbonyl)amino)-hexanoate,and p-nitrophenyl iodoacetate). In some embodiments, theheterobifunctional cross-linker is modified with functional groups,rendering it soluble in aqueous solvents for delivery as an aqueoussolution. Furthermore, in some embodiments, the aqueous solutioncontains additives (e.g., including, but not limited to, surfactants andblock copolymers). In other embodiments, a multiplicity ofhetero-bifunctional cross-linkers can be attached to a molecule, polymeror particle to serve as the cross-linking agent. In other embodiments,the heterobifunctional cross-linker is dissolved in an organic solvent(e.g., including, but not limited to, dimethyl sulfoxide). In someembodiments, the at least one wound active agent includes, but is notlimited to, trophic factors, extracellular matrices, enzymes, enzymeinhibitors, defensins, polypeptides, anti-infective agents (includingbut not limited to silver (e.g., ionic silver, elemental silver, silvernanoparticles)), buffering agents, vitamins and minerals, analgesics,anticoagulants, coagulation factors, anti-inflammatory agents,vasoconstrictors, vasodilators, diuretics, and anti-cancer agents. Insome embodiments, the at least one wound active agent contains one ormore free —SH groups.

In some embodiments, the covalent modifier is a photoactivatablecrosslinker. Suitable photoactivatable crosslinkers include, but are notlimited to, aryl azide N-((2-pyridyldithio)ethyl)-4-azidosalicylamide,4-azido-2,3,5,6-tetrafluorobenzoic acid, succinimidyl ester,4-azido-2,3,5,6-tetrafluorobenzoic acid, STP ester, benzophenonemaleimide, succinimidyl ester of 4-benzoylbenzoic acid,N-5-Azido-2-Nitrobenzoyloxysuccinimide,N-Hydroxysulfosuccinimidyl-4-azidobenzoate,N-Hydroxysuccinimidyl-4-azidosalicylic acid, and(4-[p-Azidosalicylamido]butylamine).

Referring again to FIG. 2, spatial heterogeneity is depicted in a woundby shapes 720 which depict different chemical moieties found in a woundbeds such as amine groups and sulfhydryl groups. Typical areas in awound will be amine and or sulfhydryl-rich. In some embodiments, acrosslinker (e.g., 230 in FIG. 2) comprising an activated acid is usedto react with amine groups, for example nHS (n-hydroxysuccimydal) and asecond crosslinker (e.g., 235 in FIG. 2) comprising a malemide is usedto react with sulfhydryl groups. In some embodiments, the malimide andactivated acid are conjugated to an alkyne so that a uniform surface ispresented (e.g., 240 in FIG. 2 where x represents an alkyne group). Fromthis point, widely available click chemistries can be used to adddesired wound active agents to the modified surface of the wound. Insome embodiments, the wound modifying agent is an azide conjugate orotherwise comprises an azide group and is reacted with the alkyne groupsdisplayed on the wound bed in a Huisgen Cycloaddition.

The present invention also provides kits for treating a subject having awound, comprising at least one covalent modification agent, at least onewound active agent, and instructions for using the kit to covalentlylink the at least one wound active agent to the wound. In someembodiments, the at least one covalent modification agent is ahomobifunctional cross-linker, heterobifunctional crosslinker, orphotoactivatable crosslinker as described above. In some embodiments,the at least one wound active agent includes, but is not limited towound active agents described in detail below.

The present invention also provides a kit for treating a subject havinga wound, comprising at least one covalent modification agent, at leastone wound active agent, and instructions for using the kit to covalentlylink the at least one wound active agent to the wound. In someembodiments, the at least one covalent modification agent is ahomobifunctional cross-linker. In some embodiments, the homobifunctionalcross-linker is an N-hydroxysuccinimidyl ester (e.g., including, but notlimited to, disuccinimidyl ester, dithiobis(succinimidylpropionate),3,3′-dithiobis(sulfosuccinimidylpropionate), disuccinimidyl suberate,bis(sulfosuccinimidyl)suberate, disuccinimidyl tartarate,disulfosuccinimidyl tartarate,bis[2-(succinimidyloxycarbonyloxy)ethyl]sulfone,bis[2-(sulfosuccinimidooxycarbonyloxy)ethyl]sulfone, ethyleneglycolbis(succinimidylsuccinate), ethyleneglycolbis(sulfosuccinimidylsuccinate), disuccinimidyl glutarate, andN,N′-disuccinimidylcarbonate). In some embodiments, the at least onecovalent modification agent is a heterobifunctional cross-linker (e.g.,including, but not limited to, N-succinimidyl3-(2-pyridyldithio)propionate, succinimidyl6-(3-[2-pyridyldithio]-propionamido)hexanoate, sulfosuccinimidyl6-(3′-[2-pyridyldithio]-propionamido)hexanoate,succinimidyloxycarbonyl-α-methyl-α-(2-pyridyldithio)toluene,sulfosuccinimidyl-6-[α-methyl-α-(2-pyridyldithio)toluamido]hexanoate,succinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate,sulfosuccinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate,m-maleimidobenzoyl-N-hydroxysuccinimide ester,m-maleimidobenzoyl-N-hydroxy-sulfosuccinimide ester,N-succinimidyl(4-iodoacetyl)aminobenzoate,sulfo-succinimidyl(4-iodoacetyl)aminobenzoate,succinimidyl-4-(p-maleimidophenyl)butyrate,sulfosuccinimidyl-4-(p-maleimidophenyl)butyrate,N-(γ-maleimidobutyryloxy)succinimide ester,N-(γ-maleimidobutyryloxy)sulfosuccinimide ester, succinimidyl6-((iodoacetyl)amino)hexanoate, succinimidyl6-(6-(((4-iodoacetyl)amino)hexanoyl)amino)hexanoate, succinimidyl4-(((iodoacetyl)amino)methyl)cyclohexane-1-carboxylate, succinimidyl6-((((4-iodoacetyl)amino)methyl)cyclohexane-1-carbonyl)amino)-hexanoate,and p-nitrophenyl iodoacetate). In some embodiments, the at least onewound active agent includes, but is not limited to, trophic factors(including polypeptide growth factors, neuropeptides, neurotrophins,extracellular matrices and their individual native constituents(exemplified by but not limited to laminin, fibronectin, vitronectin,collagens, also select amino acid sequences found in these proteinsknown to promote cell behaviors favorable to wound healing e.g. integrinbinding sequences exemplified by but not limited to RGD, EILDV, VCAM-1and their recombined or synthetic analogs, enzymes, enzyme inhibitors,polypeptides, antimicrobial peptides (exemplified by but not limited todefensins, magaignins, cathelocidins, bactenicin) anti-infective agents(including but not limited to silver (e.g., ionic silver, elementalsilver, silver nanoparticles)), buffering agents, vitamins and minerals,compounds that promote generation/stabilization of nitric oxide, energysources for cells, analgesics, anticoagulants, coagulation factors,anti-inflammatory agents, vasoconstrictors, vasodilators, diuretics, andanti-cancer agents. In other embodiments the kits include smallinterfering RNAs (siRNAs-also referred to as micro RNAs) that arecapable of promoting cellular behaviors conducive to the wound healingprocess. In other embodiments, the kits include compounds thatpromote/stabilize a favorable pH, osmotic environment, surface energy,surface charge, surface functionalities that enhance galvano and magnetopositive effects on wound healing, or balance of MMP/otherpeptidase/protease activity (i.e. inhibitors/promoters).

II. Wound Active Agents

In some embodiments, wound active agents are delivered to a wound bed orincorporated into a wound bed using the systems described above. In someembodiments, the wound active agent is bound covalently ornon-covalently with the polyelectrolyte layer, bead, non-covalentmodifier, etc. The present invention is not limited to a particularmechanism by which the wound active agent binds to the polyelectrolytelayer, bead, non-covalent modifier, etc.

In some embodiments, the polyelectrolyte layer, beads, or non-covalentmodifier may function as a drug delivery scaffold to deliver one or morewound active agents to the wound. Wound active agents that may bedesirable to deliver include, but are not limited to, trophic factors,extracellular matrices (ECMs), ECM fragments or synthetic constructs,enzymes, enzyme inhibitors, defensins, polypeptides, anti-infectiveagents (including antimicrobials, antivirals and antifungals), bufferingagents, vitamins and minerals, analgesics, anticoagulants, coagulationfactors, anti-inflammatory agents, vasoconstrictors, vasodilators,diuretics, and anti-cancer agents. In addition, would active agentsinclude iodine based antimicrobials such as PVP-iodine; selenium basedantimicrobials such as 7-azabenzisoselenazol-3(2H)-ones, seleniumdisulfide, and selenides; and silver based antimicrobials (e.g., silversulfadiazine, ionic silver, elemental silver, silver nanoparticles)).With respect to selenides, with the use of standard and variations oftypical protein and carbohydrate attachment chemistries, carboxyl andamino containing selenides may be routinely attached to many polymers,peptides, antibodies, steroids and drugs. Polymers and other moleculeswith attached selenides generate superoxide in a dose dependent mannerin biological solutions, in cells or attached to insoluble matrixes suchas silicones.

A wide variety of wound active agents can be incorporated into thepolyelectrolyte layer, beads, or covalent or non-covalent modifier. Thepresent invention is not limited to a particular mechanism by which oneor more wound active agents are released from the polyelectrolyte layer,beads, or covalent or non-covalent modifier into the wound. Indeed, anunderstanding of the mechanism is not necessary to practice the presentinvention. Nonetheless, in some embodiments, the present inventioncontemplates release of the one or more incorporated agents from thepolyelectrolyte layer, beads, or non-covalent modifier to the wound bydiffusion from the polyelectrolyte layer. In other embodiments, the oneor more wound active agents may be released from the polyelectrolytelayer, beads, or non-covalent modifier over time or in response to anenvironmental condition. The one or more wound active agents may beattached by a degradable linkage, such as a linkage susceptible todegradation via hydrolysis or enzymatic degradation. The linkage may beone that is susceptible to degradation at a certain pH, for example.

In some embodiments, the one or more wound active agents are applied toform a gradient with respect to the wound modifying agent. In general,the gradients present a higher contraction of wound active agent at oneor more first desired locations in the wound following application ofthe wound modifying agent to the wound and a lower concentration ofwound active agent at one or second location in the wound followingapplication of the wound modifying agent to the wound. For example, theconcentrations of the wound active agents are layered in a wound bed ina gradient such that higher concentrations of a particular compositionis greater proximal to the wound bed than distal to the wound bed in avertical fashion. The converse, where concentrations of compositions isgreater distal to the wound bed than proximal, is also contemplated.Concentration of compositions in a wound bed wherein a horizontalgradient is deposited is also contemplated. Topographical gradients arealso contemplated, wherein compositions are deposited such that theconcentrations of compositions in a wound bed or on a biocompatibleparticle follow the topography of the substrate, for example, a higherconcentration of compositions is deposited in the valleys of undulationsof an exemplary substrate compared to the peaks of the undulations.

In some embodiments, the gradient comprises a higher concentration ofthe wound active agent in the center of the wound modifying agent whichtransitions to a lower concentration of the wound active agent away fromthe center of the wound modifying agent. Accordingly, when the woundmodifying agent is applied to a wound, the gradient results in a higherconcentration of wound active agent in the center of the wound and alower concentration of wound active agent as one moves to the peripheryof the wound. In some embodiments, the gradient comprises a lowerconcentration of the wound active agent in the center of the woundmodifying agent which transitions to a higher concentration of the woundactive agent away from the center of the wound modifying agent.Accordingly, the gradient results in a lower concentration of woundactive agent in the center of the wound and a higher concentration ofwound active agent as one moves to the periphery of the wound. If two ormore wound active agents are utilized, they can be presented as similargradients or the gradients can be varied so that the concentrations ofthe two or more wound active agents vary across the wound. The gradientsof high or low concentration can be any shape, such as circular, square,rectangular, oval, oblong, etc. so that the matrix and gradient canconform to a variety of wound shapes. For example, for long, incisiontype wound, the gradient may be centered on a longitudinal axis thatextends along the length of the wound and can be centered on the wound.As another example, the gradient can be circular or oval-shaped forapplication to open type wounds, burns, sores and ulcers that areroughly circular or oval. In other embodiments, the gradients comprise aseries of features arranged in a pattern. For example, the gradients canform a series of stripes or high and low concentrations of one or morewound active agents along a longitudinal axis of the matrix.Alternatively, the gradients can form a checkerboard pattern, array,concentric circles, overlapping circles or oval, etc.

The present invention contemplates delivery of a wide variety of woundactive agents to the wound. In some embodiments, the present inventionprovides the delivery of trophic factors, including, but not limited to,agrin, amphiregulin, artemin, cardiotrophin-1, epidermal growth factorsincluding EGF; fibroblast growth factors (e.g., FGF-1, FGF-2, FGF-3,FGF-4, FGF-5, FGF-6, and FGF-7); LIF, CSF-1, CSF-2, CSF-3,erythropoietin, endothelial cell growth factors including ECGF; FGF- andECGF-related growth factors (e.g., endothelial cell stimulatingangiogenesis factor, tumor angiogenesis factor, retina-derived growthfactor (RDGF), vascular endothelium growth factor (VEGF), brain-derivedgrowth factors (BDGF-A and B), astroglial growth factors (AGF 1 and 2),omentum-derived growth factor, fibroblast-stimulating factor (FSF), andembryonal carcinoma-derived growth factor (ECDGF)); neurotrophic growthfactors (e.g, nerve growth factors (NGFs), neurturin, brain-derivedneurotrophic factor (BDNF), neurotrophin-3, neurotrophin-4, and ciliaryneurotrophic factor (CNTF)); glial growth factors (e.g., GGF-I, GGF-II,GGF-III, glia maturation factor (GMF), and glial-derived neurotrophicfactor (GDNF)); liver growth factors (e.g., hepatopoietin A,hepatopoietin B, and hepatocyte growth factors including HGF); prostategrowth factors including prostate-derived growth factors (PGFs); mammarygrowth factors including mammary-derived growth factor 1 (MDGF-1) andmammary tumor-derived factor (MTGF); heart growth factors includingnonmyocyte-derived growth factor (NMDGF); melanocyte growth factorsincluding melanocyte-stimulating hormone (MSH) and melanomagrowth-stimulating activity (MGSA); angiogenic factors (e.g.,angiogenin, angiotropin, platelet-derived ECGF, VEGF, and pleiotrophin);transforming growth factors including TGF-α and TGF-β; TGF-like growthfactors (e.g., TGF-beta₁, TGF-beta₂, TGF-beta₃, GDF-1, CDGF,tumor-derived TGF-like factors, ND-TGF, and human epithelialtransforming factor); regulatory peptides with growth factor-likeproperties (e.g., bombesin and bombesin-like peptides ranatensin andlitorin, angiotensin, endothelin, atrial natriuretic factor, vasoactiveintestinal peptide, and bradykinin); platelet-derived growth factorsincluding PDGF-A, PDGF-B, and PDGF-AB; neuropeptides (e.g., substance P,calcitonin gene-regulated peptide (CGRP), and neuropeptide Y);neurotransmitters and their analogs including norepinephrine,acetylcholine and carbachol; hedgehog, heregulin/neuregulin, IL-1,osteoclast-activating factor (OAF), lymphocyte-activating factor (LAF),hepatocyte-stimulating factor (HSF), B-cell-activating factor (BAF),tumor inhibitory factor 2 (TIF-2), keratinocyte-derived T-cell growthfactor (KD-TCGF), IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10,IL-11, stromal cell-derived cytokine (SCDC), IL-12, IL-13, IL-14, IL-15,insulin, insulin-like growth factors including IGF-1, IGF-2, and IGF-BP;interferons including INF-alpha, INF-beta, and INF-gamma; leptin,midkine, tumor necrosis factors (TNF-alpha and beta), netrins, saposins,semaphorins, somatrem, somatropin, stem cell factor, VVGF, bonemorphogenetic proteins (BMPs), adhesion molecules, other cytokines,heparin-binding growth factors, and tyrosine kinase receptor ligands. Insome embodiments, the wound active agent is a peptide such as AcEEED,which is the N terminal peptide for alpha smooth muscle actin and hasbeen shown to inhibit contractile properties of myofibroblasts.

In some embodiments, the present invention provides the delivery ofECMs, including, but not limited to native constructs, fragments ofnative constructs and synthetic analogs of: extracellular matrixproteins, reconstituted basement membrane-like complexes derived fromeukaryotic cell lines, collagens, fibronectin, laminin, VCAM-1,vitronectin and gelatin, a bacterial extracellular matrix, a gel matrix,and polymeric matrices. In some embodiments, the wound active agents areintegrin binding sequences exemplified by, but not limited to RGD,EILDV, VCAM-1 and their recombined or synthetic analogs, enzymes, enzymeinhibitors, and polypeptides.

In some embodiments, the present invention provides the delivery ofenzymes, including, but not limited to, exopeptidases and endopeptidases(also known as proteases and proteinases), including but not limited tothe serine proteinases chymotrypsin, trypsin, elastase, and kallikrein,bacterial enzymes, the cysteine proteases papain, actinin, bromelain,cathepsins, cytosolic calpains, parasitic proteases, asparticproteinases, the pepsin family of proteases pepsin and chymosin,lysosomal cathepsins D, renin, fungal proteases, the viral proteases,AIDS virus retropepsin, and the metalloproteinases (MMPs), collagenases,Maggott enzyme, MMP1, MMP2, MMP8, MMP13, gelatinases, MMP2, MMP9, MMP3,MMP7, MMP10, MMP11, and MMP12.

In some embodiments, the present invention provides the delivery ofenzyme inhibitors, including, but not limited to captopril, thiorphan,phosphoramidon, teprotide, protease and proteinase inhibitors,metalloproteinase inhibitors and exopeptidase inhibitors. In someembodiments, the present invention provides the delivery of defensins,including, but not limited to, alpha-defensins HNP 1, 2, 3 and 4, andbeta-defensins HBD-1 and HBD-2.

In some embodiments, the present invention provides the delivery ofpolypeptides, including, but not limited to, fibronectin, serotonin,PAF, PDEGF, TNFa, IL1, IL6, IGF, IGF-1, IGF-2, IL-1, PDGF, FGF, KGF,VEGF, bradykinin, prothymosin-alpha, and thymosin-alpha1.

In some embodiments, the present invention provides the delivery ofantimicrobials, including, but not limited to, magainin (e.g., magaininI, magainin II, xenopsin, xenopsin precursor fragment, caeruleinprecursor fragment), magainin I and II analogs (e.g., PGLa, magainin A,magainin G, pexiganin, Z-12, pexigainin acetate, D35, MSI-78A, MG0(K10E, K11E, F12W-magainin 2), MG2+(K10E, F12W-magainin-2), MG4+(F12W-magainin 2), MG6+ (f12W, E19Q-magainin 2 amide), MSI-238, reversedmagainin II analogs (e.g., 53D, 87-ISM, and A87-ISM), Ala-magainin IIamide, magainin II amide), cecropin P1, cecropin A, cecropin B,indolicidin, nisin, ranalexin, lactoferricin B, poly-L-lysine, cecropinA (1-8)-magainin II (1-12), cecropin A (1-8)-melittin (1-12),CA(1-13)-MA(1-13), CA(1-13)-ME(1-13), gramicidin, gramicidin A,gramicidin D, gramicidin S, alamethicin, protegrin, histatin,dermaseptin, lentivirus amphipathic peptide or analog, parasin I,lycotoxin I or II, globomycin, gramicidin S, surfactin, ralinomycin,valinomycin, polymyxin B, PM2 ((+/−) 1-(4-aminobutyl)-6-benzylindane),PM2c ((+/−)-6-benzyl-1-(3-carboxypropyl)indane), PM3((+/−)1-benzyl-6-(4-aminobutyl)indane), tachyplesin, buforin I or II,misgurin, melittin, PR-39, PR-26, 9-phenylnonylamine, (KLAKKLA)n,(KLAKLAK)n, where n=1, 2, or 3, (KALKALK)3, KLGKKLG)n, and KAAKKAA)n,wherein N=1, 2, or 3, paradaxin, Bac 5, Bac 7, ceratoxin, mdelin 1 and5, bombin-like peptides, PGQ, cathelicidin, HD-5, Oabac5alpha, ChBac5,SMAP-29, Bac7.5, lactoferrin, granulysin, thionin, hevein andknottin-like peptides, MPG1, lbAMP, snakin, lipid transfer proteins, andplant defensins. Exemplary sequences for the above compounds areprovided in Table 1. In some embodiments, the antimicrobial peptides aresynthesized from L-amino acids, while in other embodiments, the peptidesare synthesized from, or comprise, D-amino acids. Additionalantimicrobial polypeptides of use in the present invention are listed inFIG. 7.

TABLE 1 Antimicrobial Peptides SEQ ID NO: Name Organism Sequence 1lingual antimicrobial Bos taurusmrlhhlllallflvlsagsgftqgvrnsqscrrnkgicvp peptide precursorircpgsmrqigtclgaqvkccrrk (Magainin) 2 antimicrobial peptideXenopus laevis gvlsnvigylkklgtgalnavlkq PGQ 3 Xenopsin Xenopus laevismykgiflcvllavicanslatpssdadedndeveryvrgwaskigqtlgkiakvglkeliqpkreamlrsaeaqgkrpwi l 4 magainin precursorXenopus laevis mfkglficsliavicanalpqpeasadedmderevrgigkflhsagkfgkafvgeimkskrdaeavgpeafadedlderevrgigkflhsakkfgkafvgeimnskrdaeavgpeafadedlderevrgigkflhsakkfgkafvgeimnskrdaeavgpeafadedlderevrgigkflhsakkfgkafvgeimnskrdaeavgpeafadedfderevrgigkflhsakkfgkafvgeimnskrdaeavgpeafadedlderevrgigkflhsakkfgk afvgeimnskrdaeavddrrwve 5tachyplesin I Tachypleus kwcfrvcyrgicyrrcr gigas 6 tachyplesin IITachypleus rwcfrvcyrgicyrkcr gigas 7 buforin I Bufo bufomsgrgkqggkvrakaktrssraglqfpvgrvhrllrkgny gagarizansaqrvgagapvylaavleyltaeilelagnaardnkttriiprhlqlavrndeelnkllggvtiaqggvlpniqavllpkt esskpaksk 8 buforin IIBufo bufo trssraglqfpvgrvhrllrk gagarizans 9 cecropin A Bombyx morimnfvrilsfvfalvlalgavsaapeprwklfkkiekvgrn vrdglikagpaiavigqakslgk 10cecropin B Bombyx mori mnfakilsfvfalvlalsmtsaapeprwkifkkiekmgrnirdgivkagpaievlgsakaigk 11 cecropin C Drosophilamnfykifvfvalilaisigqseagwlkklgkrierigqht melanogasterrdatiqglgiaqqaanvaatarg 12 cecropin P1 Sus scrofaswlsktakklensakkrisegiaiaiqggpr 13 indolicidin Bos taurus ilpwkwpwwpwrr14 nisin Lactococcus itsislctpgcktgalmgcnmktatchcsihvsk lactis 15ranalexin Rana flgglikivpamicavtkkc catesbeiana 16 lactoferricin BBos taurus fkcrrwqwrmkklgapsitcyrraf 17 protegrin-1 Sus scrofarggrlcycrrrfcvcvgrx 18 protegrin-2 Sus scrofa ggrlcycrrrfcicvg 19histatin precursor  Homo sapiensmkffvfalilalmlsmtgadshakrhhgykrkfhekhhsh rgyrsnylydn 20 histatin 1Macaca dsheerhhgrhghhkygrkfhekhhshrgyrsnylydn fascicularis 21dermaseptin Phyllomedusa alwktmlkklgtmalhagkaalgaaadtisqtq sauvagei 22dermaseptin 2 Phyllomedusa alwftmlkklgtmalhagkaalgaaantisqgtq sauvagei23 dermaseptin 3 Phyllomedusa alwknmlkgigklagkaalgavkklvgaes sauvagei 24misgurin Misgurnus rqrveelskfskkgaaarrrk anguillicaudatus 25 melittinApis mellifera gigavlkvlttglpaliswisrkkrqq 26 pardaxin-1 Pardachirusgffalipkiissplfktllsavgsalsssgeqe pavoninus 27 pardaxin-2 Pardachirusgffalipkiisspifktllsavgsalsssggqe pavoninus 28 bactenecin 5  Bos taurusmetqraslslgrcslwllllglvlpsasaqalsyreavlr precursoravdqfnersseanlyrlleldptpnddldpgtrkpvsfrvketdcprtsqqpleqcdfkenglvkqcvgtvtldpsndqfdincnelqsvrfrppirrppirppfyppfrppirppifpp irppfrpplgpfpgrr 29 bactenecin Bos taurus metpraslslgrwslw1111glalpsasaqalsyreavlr precursoravdqlneqssepniyrlleldqppqddedpdspkrvsfrvketvcsrttqqppeqcdfkengllkrcegtvtldqvrgnfditcnnhqsiritkqpwappqaarlcrivvirvcr 30 ceratotoxin A Ceratitissigsalkkalpvakkigkialpiakaalp capitata 31 ceratotoxin B Ceratitissigsafkkalpvakkigkaalpiakaalp capitata 32 cathelicidin Homo sapiensmktqrnghslgrwslvllllglvmplaiiaqvlsykeavl antimicrobialraidginqrssdanlyrlldldprptmdgdpdtpkpvsft peptidevketvcprttqqspedcdfkkdglvkrcmgtvtlnqargsfdiscdkdnkrfallgdffrkskekigkefkrivqrikdf lrnlvprtes 33 myeloidEquus caballus metqrntrclgrwsplllllglvippattqalsykeavlr cathelicidin 3avdglnqrssdenlyrlleldplpkgdkdsdtpkpvsfmvketvcprimkqtpeqcdfkenglvkqcvgtvildpvkdyfdascdepqrvkrfhsvgsliqrhqqmirdkseatrhgiri itrpklllas 34 myeloidBos taurus metqraslslgrwslwllllglalpsasaqalsyreavlr antimicrobial avdqlneksseanlyrlleldpppkeddenpnipkpvsfr peptide BMAP-28vketvcprtsqqspeqcdfkengllkecvgtvtldqvgsnfditcavpqsvgglrslgrkilrawkkygpiivpiirig 35 myeloid Equus caballusmetqrntrclgrwsplllllglvippattqalsykeavlr cathelicidin 1avdglnqrssdenlyrlleldplpkgdkdsdtpkpvsfmvketvcprimkqtpeqcdfkenglvkqcvgtvilgpvkdhfdvscgepqrvkrfgrlaksflrmrillprrkillas 36 SMAP 29 Ovis ariesmetqraslslgrcslwllllglalpsasaqvlsyreavlraadqlneksseanlyrlleldpppkqddensnipkpvsfrvketvcprtsqqpaeqcdfkengllkecvgtvtldqvrnnfditcaepqsvrglrrlgrkiahgvkkygptvlriiriag 37 BNP-1 Bos taurusrlcrivvirvcr 38 HNP-1 Homo sapiens acycripaciagerrygtciyqgrlwafcc 39HNP-2 Homo sapiens cycripaciagerrygtciyqgrlwafcc 40 HNP-3 Homo sapiensdcycripaciagerrygtciyqgrlwafcc 41 HNP-4 Homo sapiensvcscrlvfcrrtelrvgncliggvsftycctrv 42 NP-1 Oryctolagusvvcacrralclprerragfcrirgrihplccrr cuniculus 43 NP-2 Oryctolagusvvcacrralclplerragfcrirgrihplccrr cuniculus 44 NP-3A Oryctolagusgicacrrrfcpnserfsgycrvngaryvrccsrr cuniculus 45 NP-3B Oryctolagusgrcvcrkqllcsyrerrigdckirgvrfpfccpr cuniculus 46 NP-4 Oryctolagusvsctcrrfscgfgerasgsctvnggvrhtlccrr cuniculus 47 NP-5 Oryctolagusvfctcrgflcgsgerasgsctingvrhtlccrr cuniculus 48 RatNP-1 Rattusvtcycrrtrcgfrerlsgacgyrgriyrlccr norvegicus 49 Rat-NP-3 Rattuscscrysscrfgerllsgacrlngriyrlcc norvegicus 50 Rat-NP-4 Rattusactcrigacvsgerltgacglngriylccr norvegicus 51 GPNP Guinea pigrrcicttrtcrfpyrrlgtcifqnrvytfcc 52 beta defensin-3 Homo sapiensmrihyllfallflflvpvpghggiintlqkyycrvrggrc avlsclpkeeqigkcstrgrkccrrkk 53theta defensin-1 Macaca mulatta rcictrgfcrclcrrgvc 54 defensin CUA1Helianthus mkssmkmfaalllvvmcllanemggplvveartcesqshk annuusfkgtclsdtncanvchserfsggkcrgfrrrcfctthc 55 defensin SD2 Helianthusmkssmkmfaalllvvmcllanemggplvveartcesqshk annuusfkgtclsdtncanvchserfsggkcrgfrrrcfctthc 56 neutrophil Macaca mulattaacycripaclagerrygtcfymgrvwafcc defensin 2 57 4 KDA defensin Androctonusgfgcpfnqgachrhcrsirrrggycaglfkqtctcyr australis hector 58 defensinMytilus gfgcpnnyqchrhcksipgrcggycggxhrlrctcyrc galloprovincialis 59defensin AMP1 Heuchera dgvklcdvpsgtwsghcgssskcsqqckdrehfayggachsanguinea yqfpsvkcfckrqc 60 defensin AMP1 Clitorianlcerasltwtgncgntghcdtqcrnwesakhgachkrgn ternatea wkcfcyfnc 61cysteine-rich Mus musculus mkklvllfalvllafqvqadsiqntdeetkteeqpgekdqcryptdin-1 avsvsfgdpqgsalqdaalgwgrrcpqcprcpscpscprc homolog prcprckcnpk62 beta-defensin-9 Bos taurus qgvrnfvtcrinrgfcvpircpghrrqigtclgpqikccr63 beta-defensin-7 Bos taurus qgvrnfvtcrinrgfcvpircpghrrqigtclgprikccr64 beta-defensin-6 Bos taurus qgvrnhvtcriyggfcvpircpgrtrqigtcfgrpvkccrrw 65 beta-defensin-5 Bos taurusqvvrnpqscrwnmgvcipiscpgnmrqigtcfgprvpccr 66 beta-defensin-4 Bos taurusqrvrnpqscrwnmgvcipflcrvgmrqigtcfgprvpccr 67 beta-defensin-3 Bos taurusqgvrnhvtcrinrgfcvpircpgrtrqigtcfgprikccr sw 68 beta-defensin-10Bos taurus qgvrsylscwgnrgicllnrcpgrmrqigtclaprvkccr 69 beta-defensin-13Bos taurus sgisgplscgrnggvcipircpvpmrqigtcfgrpvkccr sw 70beta-defensin-1 Bos taurus dfaschtnggiclpnrcpghmiqigicfrprvkccrsw 71coleoptericin Zophobas slqggapnfpqpsqqnggwqvspdlgrddkgntrgqieiq atratusnkgkdhdfnagwgkvirgpnkakptwhvggtyrr 72 beta defensin-3 Homo sapiensmrihyllfallflflvpvpghggiintlqkyycrvrggrc avlsclpkeeqigkcstrgrkccrrkk 73defensin C Aedes aegypti atcdllsgfgvgdsacaahciargnrggycnskkvcvcrn 74defensin B Mytilus edulis gfgcpndypchrhcksipgryggycggxhrlrctc 75sapecin C Sarcophaga atcdllsgigvqhsacalhcvfrgnrggyctgkgicvcrn peregrina76 macrophage Oryctolagus mrtlallaaillvalqaqaehvsvsidevvdqqppqaedqantibiotic cuniculus dvaiyvkehessalealgvkagvvcacrralclprerragpeptide MCP-1 fcrirgrihplccrr 77 cryptdin-2 Mus musculusmkplvllsalvllsfqvqadpiqntdeetkteeqsgeedqavsvsfgdregaslqeeslrdlvcycrtrgckrrermngt crkghlmytlcc 78 cryptdin-5Mus musculus mktfvllsalvllafqvqadpihktdeetnteeqpgeedqavsisfggqegsalheelskklicycrirgckrrervfgt crnlfltfvfccs 79 cryptdin 12Mus musculus lrdlvcycrargckgrermngtcrkghllymlccr 80 defensin Pyrrhocorisatcdilsfqsqwvtpnhagcalhcvikgykggqckitvch apterus crr 81 defensin R-5Rattus vtcycrstrcgfrerlsgacgyrgriyrlccr norvegicus 82 defensin R-2Rattus vtcscrtsscrfgerlsgacrlngriyrlcc norvegicus 83 defensin NP-6Oryctolagus gicacrrrfclnfeqfsgycrvngaryvrccsrr cuniculus 84beta-defensin-2 Pan troglodytes mrvlyllfsflfiflmplpgvfggisdpvtclksgaichp vfcprrykqigtcglpgtkcckkp 85beta-defensin-2 Homo sapiens mrvlyllfsflfiflmplpgvfggigdpvtclksgaichpvfcprrykqigtcglpgtkcckkp 86 beta-defensin-1 Homo sapiensmrtsylllftlclllsemasggnfltglghrsdhyncvss ggqclysacpiftkiqgtcyrgkakcck 87beta-defensin-1 Capra hircus mrlhhlllvlfflvlsagsgftqgirsrrschrnkgvcaltrcprnmrqigtcfgppvkccrkk 88 beta defensin-2 Capra hircusmrlhhlllalfflvlsagsgftqgiinhrscyrnkgvcap arcprnmrqigtchgppvkccrkk 89defensin-3 Macaca mrtivilaaillvalqaqaeplqartdeataaqeqiptdn mulattapevvvslawdeslapkdsvpglrknmacycripaclager rygtcfyrrrvwafcc 90 defensin-1Macaca mrtivilaaillvalqaqaeplqartdeataaqeqiptdn mulattapevvvslawdeslapkdsvpglrknmacycripaclager rygtcfylgrvwafcc 91 neutrophilMesocricetus vtcfcrrrgcasrerhigycrfgntiyrlccrr defensin 1 auratus 92neutrophil Mesocricetus cfckrpvcdsgetqigycrlgntfyrlccrq defensin 1auratus 93 Gallinacin Gallus gallusgrksdcfrkngfcaflkcpyltlisgkcsrfhlcckriw 1-alpha 94 defensin Allomyrinavtcdllsfeakgfaanhslcaahclaigrrggscergvci dichotoma crr 95 neutrophil Cavia porcellus rrcicttrtcrfpyrrlgtcifqnrvytfcc cationic peptide 1

In some embodiments, the present invention provides the delivery ofantimicrobials, including, but not limited to, loracarbef, cephalexin,cefadroxil, cefixime, ceftibuten, cefprozil, cefpodoxime, cephradine,cefuroxime, cefaclor, neomycin/polymyxin/bacitracin, dicloxacillin,nitrofurantoin, nitrofurantoin macrocrystal, nitrofurantoin/nitrofuranmac, dirithromycin, gemifloxacin, ampicillin, gatifloxacin, penicillin Vpotassium, ciprofloxacin, enoxacin, amoxicillin, amoxicillin/clavulanatepotassium, clarithromycin, levofloxacin, moxifloxacin, azithromycin,sparfloxacin, cefdinir, ofloxacin, trovafloxacin, lomefloxacin,methenamine, erythromycin, norfloxacin, clindamycin/benzoyl peroxide,quinupristin/dalfopristin, doxycycline, amikacin sulfate, vancomycin,kanamycin, netilmicin, streptomycin, tobramycin sulfate, gentamicinsulfate, tetracyclines, framycetin, minocycline, nalidixic acid,demeclocycline, trimethoprim, miconazole, colistimethate, piperacillinsodium/tazobactam sodium, paromomycin, colistin/neomycin/hydrocortisone,amebicides, sulfisoxazole, pentamidine, sulfadiazine, clindamycinphosphate, metronidazole, oxacillin sodium, nafcillin sodium, vancomycinhydrochloride, clindamycin, cefotaxime sodium, co-trimoxazole,ticarcillin disodium, piperacillin sodium, ticarcillindisodium/clavulanate potassium, neomycin, daptomycin, cefazolin sodium,cefoxitin sodium, ceftizoxime sodium, penicillin G potassium and sodium,ceftriaxone sodium, ceftazidime, imipenem/cilastatin sodium, aztreonam,cinoxacin, erythromycin/sulfisoxazole, cefotetan disodium, ampicillinsodium/sulbactam sodium, cefoperazone sodium, cefamandole nafate,gentamicin, sulfisoxazole/phenazopyridine, tobramycin, lincomycin,neomycin/polymyxin B/gramicidin, clindamycin hydrochloride,lansoprazole/clarithromycin/amoxicillin, alatrofloxacin, linezolid,bismuth subsalicylate/metronidazole/tetracycline, erythromycin/benzoylperoxide, mupirocin, fosfomycin, pentamidine isethionate,imipenem/cilastatin, troleandomycin, gatifloxacin, chloramphenicol,cycloserine, neomycin/polymyxin B/hydrocortisone, ertapenem, meropenem,cephalosporins, fluconazole, cefepime, sulfamethoxazole,sulfamethoxazole/trimethoprim, neomycin/polymyxin B, penicillins,rifampin/isoniazid, erythromycin estolate, erythromycin ethylsuccinate,erythromycin stearate, ampicillin trihydrate, ampicillin/probenecid,sulfasalazine, sulfanilamide, sodium sulfacetamide, dapsone, doxycyclinehyclate, trimenthoprim/sulfa, methenamine mandelate, plasmodicides,pyrimethamine, hydroxychloroquine, chloroquine phosphate,trichomonocides, anthelmintics, atovaquone, bacitracin,bacitracin/polymyxin b, gentamycin, neomycin/polymyxin/dexameth,neomycin sulf/dexameth, sulfacetamide/prednisolone,sulfacetamide/phenylephrine, tobramycin sulfate/dexameth, bismuthtribromophenate, silver ion compounds, silver nanoparticles, zerovalentsilver, multivalent silver, elemental silver, and silver containingcompounds such as silver sulfadiazine and related compounds.

In some embodiments, the present invention provides the delivery ofantivirals, including, but not limited to, amantadine, acyclovir,foscarnet, indinavir, ribavirin, enfuvirtide, emtricitabine, lamivudine,abacavir sulfate, fomivirsen, valacyclovir, tenofovir, cidofovir,atazanavir, amprenavir, delavirdine mesylate, famciclovir, adefovir,didanosine, efavirenz, trifluridine, inidinavir, lamivudine, vidarabine,lopinavir/ritonavir, ganciclovir, zanamivir,abacavir/lamivudine/zidovudine, lamivudine/zidovudine, nelfinavir,nelfinavir mesylate, nevirapine, ritonavir, saquinavir, saquinavirmesylate, rimantadine, stavudine, docosanol, zalcitabine, idoxuridine,zidovudine, zidovudine/didanosine, valganciclovir, penciclovir,lamivudine, and oseltamivir.

In some embodiments, the present invention provides the delivery ofantifungals, including, but not limited to, amphotericin B, nystatin,nystatin/triamcinolone, itraconazole, ketoconazole, miconazole,sulconazole, clotrimazole, clotrimazole/betamethasone, enilconazole,econazole, oxiconazole, tioconazole, terconazole, butoconazole,thiabendazole, flucytosine, butenafine, ciclopirox, haloprogin,naftifine, tolnaftate, natamycin, undecylenic acid, mafenide, dapsone,clioquinol, clioquinol/hydrocortisone, potassium iodide, silversulfadiazine, gentian violet, carbol-fuchsin, cilofungin, sertaconazole,voriconazole, fluconazole, terbinafine, caspofungin, other topical azoledrugs, and griseofulvin.

In some embodiments, the present invention provides the use and deliveryof buffering agents, including, but not limited to, Maleic acid,Phosphoric acid, Glycine, Chloroacetic acid, Formic acid, Benzoic acid,Acetic acid, Pyridine, Piperazine, MES, Bis-tris, Carbonate, ACES, ADAMOPSO, PIPES, Phosphoric acid, BES, MOPS, TES, HEPES, DIPSO, TAPSO,Triethanolamine, HEPSO, Tris, Tricine, Bicine, TAPS, Borate, Ammonia,CHES, Ethanolamine, CAPSO, Glycine, Carbonate, CAPS, Methylamine,Piperidine, and Phosphoric acid.

In some embodiments, the present invention provides the delivery ofvitamins and minerals, including, but not limited to, Vitamin A,Carotenoids, Vitamin D, Vitamin E, Vitamin K, Vitamin C/ascorbic acid,B1/thiamin, B2/riboflavin, B3/niacin, B5/pantothenic acid,B6/pyridoxine, B12/cobalamin, Biotin, Calcium, Magnesium, Phosphorus,Sodium, Chloride, Potassium, Boron, Chromium, Copper, Iodine, Iron,Manganese, Selenium, and Zinc.

In some embodiments, the present invention provides the delivery ofanalgesics, including, but not limited to, acetaminophen, anileridine,acetylsalicylic acid, buprenorphine, butorphanol, fentanyl, fentanylcitrate, codeine, rofecoxib, hydrocodone, hydromorphone, hydromorphonehydrochloride, levorphanol, alfentanil hydrochloride, meperidine,meperidine hydrochloride, methadone, morphine, nalbuphine, opium,levomethadyl, hyaluronate sodium, sufentanil citrate, capsaicin,tramadol, leflunomide, oxycodone, oxymorphone, celecoxib, pentazocine,propoxyphene, benzocaine, lidocaine, dezocine, clonidine, butalbital,phenobarbital, tetracaine, phenazopyridine,sulfamethoxazole/phenazopyridine, and sulfisoxazole/phenazopyridine.

In some embodiments, the present invention provides the delivery ofanticoagulants, including, but not limited to, coumarins,1,3-indandione, anisindione, fondaparinux, heparin, lepirudin,antithrombin, warfarin, enoxaparin, dipyridamole, dalteparin, ardeparin,nadroparin, and tinzaparin.

In some embodiments, the present invention provides the delivery ofcoagulation factors, including, but not limited to, Factor I(fibrinogen), Factor II (prothrombin), Factor III (thromboplastin,tissue factor), Factor IV (calcium), Factor V (labile factor), FactorVII (stable factor), Factor VIII (antihemophilic globulin,antihemophilic globulin, antihemophilic factor A), Factor IX (plasmathromboplastin component, Christmas factor, antihemophilic factor B),Factor X (Stuart factor, Prower factor, Stuart-Prower factor), Factor XI(plasma thromboplastin antecedent, antihemophilic factor C), Factor XII(Hageman factor, surface factor, contact factor), and Factor XIII(fibrin stabilizing factor, fibrin stabilizing enzyme, fibri-nase).

In some embodiments, the present invention provides the delivery ofanti-inflammatory agents, including, but not limited to, non steroidalanti-inflammatory drugs (NSAIDs) including diclofenac (also known asVoltaren, Abitren, Allvoran, Almiral, Alonpin, Anfenax, Artrites,Betaren, Blesin, Bolabomin, Cataflam, Clofec, Clofen, Cordralan,Curinflam, Diclomax, Diclosian, Dicsnal, Difenac, Ecofenac, Hizemin,Inflamac, Inflanac, Klotaren, Lidonin, Monoflam, Naboal, Oritaren,Remethan, Savismin, Silino, Staren, Tsudohmin, Voltarol, Voren, Voveran,and Vurdon), diflunisal (also known as Dolobid, Adomal, Diflonid,Diflunil, Dolisal, Dolobis, Dolocid, Donobid, Dopanone, Dorbid, Dugodol,Flovacil, Fluniget, Fluodonil, Flustar, Ilacen, Noaldol, Reuflos, andUnisal), etodolac (also known as Lodine), fenoprofen (also known asNalfon, Fenoprex, Fenopron, Fepron, Nalgesic, and Progesic),flurbiprofen (also known as Ansaid and Ocuflur), ibuprofen (also knownas Rufen, Motrin, Aches-N-Pain, Advil, Nuprin, Dolgesic, Genpril,Haltran, Ibifon, Ibren, Ibumed, Ibuprin, Ibupro-600, Ibuprohm, Ibu-Tab,Ibutex, Ifen, Medipren, Midol 200, Motrin-IB, Cramp End, Profen,Ro-Profen, Trendar, Alaxan, Brofen, Alfam, Brufen, Algofen, Brufort,Amersol, Bruzon, Andran, Buburone, Anflagen, Butacortelone, Apsifen,Deflem, Artofen, Dolgit, Artril, Dolocyl, Bloom, Donjust, Bluton,Easifon, Ebufac, Emflam, Emodin, Fenbid, Fenspan, Focus, Ibosure,Ibufen, Ibufug, Ibugen, Ibumetin, Ibupirac, Imbun, Inabrin, Inflam,Irfen, Librofen, Limidon, Lopane, Mynosedin, Napacetin, Nobafon, Nobgen,Novogent, Novoprofen, Nurofen, Optifen, Paduden, Paxofen, Perofen,Proartinal, Prontalgin, Q-Profen, Relcofen, Remofen, Roidenin, Seclodin,Tarein, and Zofen), indomethacin (also known as Indameth, Indocin,Amuno, Antalgin, Areumatin, Argilex, Artherexin, Arthrexin, Artrinovo,Bavilon, Bonidon, Boutycin, Chrono-Indocid, Cidalgon, Confortid,Confortind, Domecid, Durametacin, Elemetacin, Idicin, Imbrilon, Inacid,Indacin, Indecin, Indocap, Indocen, Indocid, Indoflex, Indolag, Indolar,Indomed, Indomee, Indometacinum, Indometicina, Indometin, Indovis,Indox, Indozu, Indrenin, Indylon, Inflazon, Inpan, Lauzit, Liometace,Metacen, Metindon, Metocid, Mezolin, Mobilan, Novomethacin, Peralgon,Reflox, Rheumacid, Rheumacin, Salinac, Servindomet, Toshisan, andVonum), ketoprofen (also known as Orudis, Alrheumat, Alrheumun,Alrhumat, Aneol, Arcental, Dexal, Epatec, Fastum, Keduril, Kefenid,Keprofen, Ketofen, Ketonal, Ketosolan, Kevadon, Mero, Naxal, Oruvail,Profenid, Salient, Tofen, and Treosin), ketorolac (also known asToradol), meclofenamate (also known as Meclofen, Meclomen, and Movens),mefenamic acid (also known as Ponstel, Alpain, Aprostal, Benostan,Bonabol, Coslan, Dysman, Dyspen, Ecopan, Lysalgo, Manic, Mefac, Mefic,Mefix, Parkemed, Pondex, Ponsfen, Ponstan, Ponstyl, Pontal, Ralgec, andYoufenam), nabumetone (also known as Relafen), naproxen (also known asNaprosyn, Anaprox, Aleve, Apranax, Apronax, Arthrisil, Artrixen,Artroxen, Bonyl, Congex, Danaprox, Diocodal, Dysmenalgit, Femex, Flanax,Flexipen, Floginax, Gibixen, Headlon, Laraflex, Laser, Leniartil,Nafasol, Naixan, Nalyxan, Napoton, Napren, Naprelan, Naprium, Naprius,Naprontag, Naprux, Napxen, Narma, Naxen, Naxid, Novonaprox, Nycopren,Patxen, Prexan, Prodexin, Rahsen, Roxen, Saritilron, Sinartrin, Sinton,Sutony, Synflex, Tohexen, Veradol, Vinsen, and Xenar), oxaprozin (alsoknown as Daypro), piroxicam (also known as Feldene, Algidol, Antiflog,Arpyrox, Atidem, Bestocam, Butacinon, Desinflam, Dixonal, Doblexan,Dolonex, Feline, Felrox, Fuldin, Indene, Infeld, Inflamene, Lampoflex,Larapam, Medoptil, Novopirocam, Osteral, Pilox, Piraldene, Piram, Pirax,Piricam, Pirocam, Pirocaps, Piroxan, Piroxedol, Piroxim, Piton,Posidene, Pyroxy, Reucam, Rexicam, Riacen, Rosic, Sinalgico, Sotilen,Stopen, and Zunden), sulindac (also known as Clinoril, Aflodac,Algocetil, Antribid, Arthridex, Arthrocine, Biflace, Citireuma,Clisundac, Imbaral, Lindak, Lyndak, Mobilin, Reumofil, Sudac, Sulene,Sulic, Sulindal, Suloril, and Sulreuma), tolmetin (also known asTolectin, Donison, Midocil, Reutol, and Safitex), celecoxib (also knownas Celebrex), meloxicam (also known as Mobic), rofecoxib (also known asVioxx), valdecoxib (also known as Bextra), aspirin (also known asAnacin, Ascriptin, Bayer, Bufferin, Ecotrin, and Excedrin) and steroidalanti-inflammatory drugs including cortisone, prednisone anddexamethasone.

In some embodiments, the present invention provides the delivery ofvasoconstrictors, including, but not limited to, epinephrine(adrenaline, Susphrine), phenylephrine hydrochloride (Neo-Synephrine),oxymetazoline hydrochloride (Afrin), norepinephrine (Levophed), andcaffeine.

In some embodiments, the present invention provides the delivery ofvasodilators, including, but not limited to, bosentan (Tracleer),epoprostenol (Flolan), treprostinil (Remodulin), sitaxsentan, nifedipine(Adalat, Procardia), nicardipine (Cardene), verapamil (Calan, Covera-HS,Isoptin, Verelan), diltiazem (Dilacor XR, Diltia XT, Tiamate, Tiazac,Cardizem), isradipine (DynaCirc), nimodipine (Nimotop), amlodipine(Norvasc), felodipine (Plendil), nisoldipine (Sular), bepridil (Vascor),hydralazine (Apresoline), minoxidil (Loniten), isosorbide dinitrate(Dilatrate-SR, Iso-Bid, Isonate, Isorbid, Isordil, Isotrate,Sorbitrate), isorbide mononitrate (IMDUR), prazosin (Minipress),cilostazol (Pletal), treprostinil (Remodulin), cyclandelate, isoxsuprine(Vasodilan), nylidrin (Arlidin), nitrates (Deponit, Minitran, Nitro-Bid,Nitrodisc, Nitro-Dur, Nitrol, Transderm-Nitro), benazepril (Lotensin),benazepril and hydrochlorothiazide (Lotensin HCT), captopril (Capoten),captopril and hydrochlorothiazide (Capozide), enalapril (Vasotec),enalapril and hydrochlorothiazide (Vaseretic), fosinopril (Monopril),lisinopril (Prinivil, Zestril), lisinopril and hydrochlorothiazide(Prinzide, Zestoretic), moexipril (Univasc), moexipril andhydrochlorothiazide (Uniretic), perindopril (Aceon), quinapril(Accupril), quinapril and hydrochlorothiazide (Accuretic), ramipril(Altace), trandolapril (Mavik), papaverine (Cerespan, Genabid, Pavabid,Pavabid HP, Pavacels, Pavacot, Pavagen, Pavarine, Pavased, Pavatine,Pavatym, Paverolan).

In some embodiments, the present invention provides the delivery ofdiuretics, including, but not limited to, acetazolamide (Diamox),dichlorphenamide (Daranide), methazolamide (Neptazane),bendroflumethiazide (Naturetin), benzthiazide (Exna), chlorothiazide(Diuril), chlorthalidone (Hygroton), hydrochlorothiazide (Esidrix,HydroDiuril, Microzide), hydroflumethiazide (Diucardin), indapamide(Lozol), methyclothiazide (Enduron), metolazone (Zaroxolyn, Mykrox),polythiazide (Renese), quinethazone (Hydromox), trichlormethiazide(Naqua), bumetanide (Bumex), ethacrynic acid (Edecrin), furosemide(Lasix), torsemide (Demadex), amiloride (Midamor), amiloride andhydrochlorothiazide (Moduretic), spironolactone (Aldactone),spironolactone and hydrochlorothiazide (Aldactazide), triamterene(Dyrenium), triamterene and hydrochlorothiazide (Dyazide, Maxzide).

In some embodiments, the present invention provides the delivery ofanti-cancer agents, including, but not limited to, aldesleukin,alemtuzumab, alitretinoin, allopurinol, altretamine, amifostine,anagrelide, anastrozole, arsenic trioxide, asparaginase, bexarotene,bicalutamide, bleomycin, busulfan, calusterone, capecitabine,carboplatin, carmustine, celecoxib, chlorambucil, cisplatin, cladribine,cyclophosphamide, cytarabine, dacarbazine, dactinomycin, darbepoetinalpha, daunorubicin, daunomycin, dexrazoxane, docetaxel, doxorubicin,epoetin alpha, estramustine, etoposide, etoposide phosphate, exemestane,filgrastim, floxuridine, fludarabine, flutamide, fulvestrant,gemcitabine, gemtuzumab ozogamicin, goserelin acetate, hydroxyurea,ibritumomab tiuxetan, idarubicin, ifosfamide, imatinib mesylate,interferon alpha-2a, interferon alpha-2b, irinotecan, leflunomide,letrozole, leucovorin, levamisole, lomustine, meclorethamine (nitrogenmustard), megestrol acetate, melphalan, mercaptopurine, mesna,methotrexate, methoxsalen, mitomycin C, mitotane, mitoxantrone,mycophenolate mofetil, nandrolone phenpropionate, nilutamide,nofetumomab, oprelvekin, oxaliplatin, paclitaxel, pamidronate,pegademase, pegaspargase, pegfilgrastim, pentostatin, pipobroman,plicamycin, porfimer sodium, procarbazine, quinacrine, rasburicaserituximab, sargramostim, streptozocin, tacrolimus, tamoxifen,temozolomide, teniposide, testolactone, thioguanine, thiotepa,topotecan, toremifene, tositumomab, trastuzumab, tretinoin, uracilmustard, valrubicin, vinblastine, vincristine, vinorelbine, andzoledronate.

In other embodiments, the wound active agent is an siRNA. The RNAiconstructs of the present invention are gene(s) that express RNAs thatbase pair to form a dsRNA RNA region. The RNAs may be a part of the samemolecule or different molecules. In preferred embodiments, the RNAiconstruct comprises a promoter operably linked to a nucleic acidsequence encoding two complementary sequences separated by a loopsequence. The complementary regions correspond to a target RNA sequenceseparated by a loop sequence. When the RNAi construct is expressed, thecomplementary regions of the resulting RNA molecule pair with oneanother to form a double stranded RNA region. The present invention isnot limited to loop sequences of any particular length. In somepreferred embodiments, the loop sequences range from about 4 to about 20nucleotides in length. In more preferred embodiments, the loop sequencesare from about 6 to about 12 nucleotides in length. In other preferredembodiments, the dsRNA regions are from about 19 to about 23 in length.

In other embodiments, the dsRNA is formed from RNA transcribed from avector as two separate stands. In other embodiments, the two strands ofDNA used to form the dsRNA may belong to the same or two differentduplexes in which they each form with a DNA strand of at least partiallycomplementary sequence. When the dsRNA is thus-produced, the DNAsequence to be transcribed is flanked by two promoters, one controllingthe transcription of one of the strands, and the other that of thecomplementary strand. These two promoters may be identical or different.In some embodiments, a DNA duplex provided at each end with a promotersequence can directly generate RNAs of defined length, and which canjoin in pairs to form a dsRNA. See, e.g., U.S. Pat. No. 5,795,715,incorporated herein by reference. RNA duplex formation may be initiatedeither inside or outside the cell.

It will be recognized that after processing the resulting siRNA cancomprise two blunt ends, one blunt end and one end with an overhang, ortwo ends with overhangs. In some embodiments, the end or ends withoverhangs comprise an overhang of either one or two nucleotides. As anon-limiting example, a siRNA of 23 nucleotides in length comprises two19mers with a two nucleotide overhang at each end. As anothernon-limiting example, a siRNA of 21 nucleotides in length comprises two19mers with a single nucleotide overhang at each end. As still anothernon-limiting example, a siRNA of 22 nucleotides in length comprises two22mers with no overhangs at either end.

Inhibition is sequence-specific in that nucleotide sequencescorresponding to the duplex region of the RNA are targeted for geneticinhibition. RNA molecules containing a nucleotide sequence identical toa portion of the target gene are preferred for inhibition. RNA sequenceswith insertions, deletions, and single point mutations relative to thetarget sequence have also been found to be effective for inhibition.Thus, sequence identity may optimized by sequence comparison andalignment algorithms known in the art (see Gribskov and Devereux,Sequence Analysis Primer, Stockton Press, 1991, and references citedtherein) and calculating the percent difference between the nucleotidesequences by, for example, the Smith-Waterman algorithm as implementedin the BESTFIT software program using default parameters (e.g.,University of Wisconsin Genetic Computing Group). Greater than 90%sequence identity, or even 100% sequence identity, between theinhibitory RNA and the portion of the target gene is preferred.Alternatively, the duplex region of the RNA may be defined functionallyas a nucleotide sequence that is capable of hybridizing with a portionof the target gene transcript.

There is no upper limit on the length of the dsRNA that can be used. Forexample, the dsRNA can range from about 21 base pairs (bp) of the geneto the full length of the gene or more. In one embodiment, the dsRNAused in the methods of the present invention is about 1000 bp in length.In another embodiment, the dsRNA is about 500 bp in length. In yetanother embodiment, the dsRNA is about 22 bp in length. In somepreferred embodiments, the sequences that mediate RNAi are from about 21to about 23 nucleotides. The isolated iRNAs of the present inventionmediate degradation of the target RNA.

The double stranded RNA of the present invention need only besufficiently similar to natural RNA that it has the ability to mediateRNAi for the target RNA. In one embodiment, the present inventionrelates to RNA molecules of varying lengths that direct cleavage ofspecific mRNA to which their sequence corresponds. It is not necessarythat there be perfect correspondence of the sequences, but thecorrespondence must be sufficient to enable the RNA to direct RNAicleavage of the target mRNA. In a particular embodiment, the RNAmolecules of the present invention comprise a 3′ hydroxyl group.

III. Matrix Compositions

In some embodiments, the present invention provides compositionscomprising a matrix that can be applied to a wound. In some embodiments,the matrix is functionalized. In some embodiments, the matrix comprisesone or more polymers, preferably biocompatible, or is formed from onemore proteins, or is a combination of polymers and proteins. The matrixis preferably functionalized to allow for covalent interaction and/orbinding to the wound bed, or to allow application of wound active agentsto the matrix. In some embodiments, a wound active agent, for example anantimicrobial agent such as a solver compound, is incorporated into thematrix. In some embodiments, the matrix is formed or provided on a solidsupport. The solid support can form an outer permeable, semi-permeable,or impermeable barrier after application of the matrix to a wound or canserve as a removed support for transfer and application of the matrix tothe wound followed by removal of the support. The present invention isnot limited to any particular solid support. Indeed, a variety of solidsupports are contemplated, including, but not limited to, solid supportsformed from elastomeric materials such PDMS, nylon, Teflon®, Gortex®,silk, polyurethane, silicon, preferably medical grade silicon, PVDF, andsolids supports formed from polyvinyl alcohol and polyethylene oxide. Insome embodiments, the solid support is a wound dressing that iscompatible with functionalization by addition of a matrix material.Examples of commercially available wound dressings that can be modifiedby addition of a matrix as described below include, but are not limitedto, Biobrane™, gauze, adhesive tape, bandages such as Band-Aids®, andother commercially available wound dressings including but not limitedto COMPEEL®, DUODERM™, TAGADERM™ and OPSITE®.

In some embodiments, the matrices, such as polymer multilayers, arenanoscale to microscale in dimension. Accordingly, in some embodiments,the matrices are from about 1 nm to 1000 nm thick, from about 1 nm to500 nm thick, from about 1 nm to 100 nm thick, from about 1 nm to about25 nm thick, from about 1 nm to about 10 nm thick, or less than about500 nm, 100 nm, 25 nm or 10 nm thick. It is contemplated that thenanoscale dimension of the matrices (i.e., the nanoscale thickness)allows for the loading of a lower total amount of an active agent whilestill allowing delivery of an effective amount (i.e., an amount ofactive agent that accelerates wound healing as compared to controls) ofthe active agent as compared to matrix structures with greaterthickness. It is contemplated that the lower total loading levels resultin reduced toxicity in the wound environment, especially whenantimicrobial compounds are incorporated into the polymer multilayer.

In some embodiments, the compliance of the matrices, such as polymermultilayers, is adjusted to facilitate cell migration in the wound. Insome embodiments, the matrices have a compliance, measured inkilopascals (kPa) of from about 3 to about 500 kPa, about 7 to about 250kPa, about 10 to about 250 kPA or from about 10 to about 200 kPa. Insome embodiments, the matrices, e.g., polymer multilayers, have acompliance of from about 3 kPa to 5, 4, 3, 2, 1, 0.5, 0.1 and 0.05 GPa(gigapascals).

A. Polymer Matrix Materials

In some embodiments, the matrix is a polymer multilayer. In someembodiments, the multilayer structures comprise layers ofpolyelectrolytes (i.e., forming a polyelectrolyte multilayer), while inother embodiments, the multilayers comprise polymers that do not have acharge (i.e., non-ionic polymers) or a combination of charged anduncharged polymer layers. In some embodiments, it is contemplated thatpolyelectrolyte films built-up by the alternated adsorption of cationicand anionic polyelectrolyte layers constitute a novel and promisingtechnique to modify wound surfaces in a controlled way [(Decher et al.,1992, Thin Solid Films 210/211:831; Decher, 1997, Science 277:1232). Oneof the most important properties of such multilayers is that theyexhibit an excess of alternatively positive and negative charges (Carusoet al., 1999, J Am Chem Soc 121:6039; Ladam et al., 2000, Langmuir16:1249). Not only can this constitute the motor of their buildup(Joanny, 1999, Eur. Phys. J. Biol. 9:117), but it allows, by simplecontact, to adsorb a great variety of compounds such as dyes, particles(Cassagneau et al., 1998, J. Am. Chem. Soc. 120:7848; Caruso et al.,1999, Langmuir 15:8276; Lvov et al., 1997, Langmuir 13:6195), claymicroplates (Ariga et al., 1999, Appl. Clay Sci. 15:137) and proteins(Keller et al., 1994, J. Am. Chem. Soc. 116:8817; Lvov et al., 1995, J.Am. Chem. Soc. 117:6117; Caruso et al., 1997, Langmuir 13:3427).

Polyelectrolyte layers are formed by alternating applications of anionicpolyelectrolytes and cationic polyelectrolytes to surfaces to form apolyelectrolyte multilayer. In some embodiments, one or more woundactive agents, such as those described above, are incorporated into themultilayer. Preferably, at least four layers, and, more preferably, atleast six layers are used to form the polyelectrolyte multilayer.

Cationic polyelectrolytes useful in the present invention can be anybiocompatible water-soluble polycationic polymer, for example, anypolymer having protonated heterocycles attached as pendant groups. Asused herein, “water soluble” means that the entire polymer must besoluble in aqueous solutions, such as buffered saline or buffered salinewith small amounts of added organic solvents as co-solvents, at atemperature between 20 and 37° Centigrade. In some embodiments, thematerial will not be sufficiently soluble (defined herein as soluble tothe extent of at least one gram per liter) in aqueous solutions per sebut can be brought into solution by grafting the polycationic polymerwith water-soluble polynonionic materials such as polyethylene glycol.

Representative cationic polyelectrolytes include natural and unnaturalpolyamino acids having net positive charge at neutral pH, positivelycharged polysaccharides, and positively charged synthetic polymers.Examples of suitable polycationic materials include polyamines havingamine groups on either the polymer backbone or the polymer side chains,such as poly-L-lysine (PLL) and other positively charged polyamino acidsof natural or synthetic amino acids or mixtures of amino acids,including, but not limited to, poly(D-lysine), poly(ornithine),poly(arginine), and poly(histidine), and nonpeptide polyamines such aspoly(aminostyrene), poly(aminoacrylate), poly(N-methyl aminoacrylate),poly(N-ethylaminoacrylate), poly(N,N-dimethyl aminoacrylate),poly(N,N-diethylaminoacrylate), poly(aminomethacrylate), poly(N-methylamino-methacrylate), poly(N-ethyl aminomethacrylate), poly(N,N-dimethylaminomethacrylate), poly(N,N-diethyl aminomethacrylate),poly(ethyleneimine), polymers of quaternary amines, such aspoly(N,N,N-trimethylaminoacrylate chloride),poly(methyacrylamidopropyltrimethyl ammonium chloride), and natural orsynthetic polysaccharides such as chitosan.

In general, the polymers must include at least five charges, and themolecular weight of the polycationic material must be sufficient toyield the desired degree of binding to a tissue or other surface, havinga molecular weight of at least 1000 g/mole.

Polyanionic materials useful in the present invention can be anybiocompatible water-soluble polyanionic polymer, for example, anypolymer having carboxylic acid groups attached as pendant groups.Suitable materials include alginate, carrageenan, furcellaran, pectin,xanthan, hyaluronic acid, heparin, heparan sulfate, chondroitin sulfate,dermatan sulfate, dextran sulfate, poly(meth)acrylic acid, oxidizedcellulose, carboxymethyl cellulose and crosmarmelose, synthetic polymersand copolymers containing pendant carboxyl groups, such as thosecontaining maleic acid or fumaric acid in the backbone. Polyaminoacidsof predominantly negative charge are also suitable. Examples of thesematerials include polyaspartic acid, polyglutamic acid, and copolymersthereof with other natural and unnatural amino acids. Polyphenolicmaterials such as tannins and lignins can be used if they aresufficiently biocompatible. Preferred materials include alginate,pectin, carboxymethyl cellulose, heparin and hyaluronic acid.

In some embodiments, the cationic polyelectrolyte used is PLL and theanionic polyelectrolyte used is poly(L-glutamic acid) (PGA). Indeed, theuse of a variety of polyelectrolytes is contemplated, including, but notlimited to, poly(ethylene imine) (PEI), poly(allylamine hydrochloride)(PAH), poly(sodium 4-styrenesulfonate) (PSS), poly(acrylic acid) (PAC),poly(maleic acid-co-propylene) (PMA-P), and poly(vinyl sulfate) (PVS).It is also possible to use naturally occurring polyelectrolytes,including hyaluronic acid and chondroitin sulfate. In still furtherembodiments, the polymer is a dendrimer, grafted polymer, or stararchitecture polymer.

In some embodiments, the multilayer structures are formed from unchargedpolymers or from a combination of charged and uncharged polymers.Examples of uncharged polymers include, but are not limited to, dextran,dextran sulfate, diethylaminoethyl (DEAE)-dextran, hydroxyethylcellulose, ethyl(hydroxyethyl) cellulose, acrylamide, polyethyleneoxide, polypropylene oxide, polyethylene oxide-polypropylene oxidecopolymers, PAAN_(a), Ficoll, polyvinylpyrolidine, and polyacrylic acid.

In some embodiments, the multilayer structures are formed from one ormore amphoteric polymers, alone in combination with the other polymersdescribed herein. In some embodiments, the amphoteric polymers compriseone or more of acrylic acid (AA), DMAEMA (dimethylaminoethylmethacrylate), APA (2-aminopropyl acrylate), MorphEMA (morpholinoethylmethacrylate), DEAEMA (diethylaminoethyl methacrylate), t-ButylAEMA(t-butylaminoethyl methacrylate), PipEMA (piperidinoethyl methacrylate),AEMA (aminoethyl methacrylate), HEMA (2-hydroxyethyl methacrylate), MA(methyl acrylate), MAA (methacrylic acid) APMA (2-aminopropylmethacrylate), AEA (aminoethyl acrylate). In some embodiments, theamphoteric polymer comprises (a) carboxylic acid, (b) primary amine, and(c) secondary and/or tertiary amine. The amphoteric polymers have anisoelectric point of 4 to 8, preferably 5 to 7 and have a number averagemolecular weight in the range of 10,000 to 150,000.

Polymer layers may be formed by a variety of methods. In someembodiments, the polymer layers are formed on solid supports asdescribed in detail below. In some embodiments, it is contemplated thatthe polymer or polymer multilayers is formed by sequential applicationof polymers using either a pump (including syringes, ink jet printers,and electrojets) or spray, such as an aerosol spray. In otherembodiments, particle bombardment is utilized. In other embodiments, theuse of a brush including an air brush is contemplated. In otherembodiments, a sponge is utilized. In other embodiments a solid supportor stamp such as an elastomeric material, for example, PDMS(polydimethylsiloxane), silicone, hydrogel or latex, is used to supportthe polymer layer and mechanically transfer the polymer layer into oronto the wound bed.

In some embodiments, the matrix comprises one or more proteins. Inpreferred embodiments, the proteins form a hydrogel. In some preferredembodiments, the matrix comprises one or more extracellular matrixproteins. In some embodiments, the matrix comprises at least one ofcollagen, laminin, vitronectin, fibronectin, keratin, and combinationsthereof. As described above, the protein matrix may preferably be formedby a variety of methods. In some embodiments, the protein matrix isformed on solid supports as described in detail below. In someembodiments, it is contemplated that the protein matrix is formed byapplication of proteins or solutions or gels of proteins using either apump (including syringes, ink jet printers, and electrojets) or spray,such as an aerosol spray. In other embodiments, the use of a brushincluding an air brush is contemplated. In other embodiments, a spongeis utilized. In other embodiments a solid support or stamp such as anelastomeric material, for example, PDMS (polydimethylsiloxane),silicone, hydrogel or latex, is used to support the protein matrix andmechanically transfer the protein matrix into or onto the wound bed.

In some embodiments, the matrix is further modified to include cells,including, but not limited to, stem cells, keratinocytes, 3-D skinconstructs, corneal epithelial cells, conjunctival cells, corneal limbalstem cell, human embryonic stem cells, pluripotential stem cells, adultinduced stem cells, hematopoietic stem cells, hepatocytes, pancreaticcells and the like. In some embodiments, the compositions and methodsdescribed herein are used to functionalize harvested and processed(frozen, freeze dried, fixed and stored dry or wet, fresh tissue fordirect transplant) animal and human tissue (pig/human aortic valve,harvested human amniotic membrane, human cadaver skin, harvested scleraand cornea, harvested cadaver bone, harvested blood vessels and thelike. In some embodiments, the compositions and methods described hereinare used to functionalize skin constructs, including, but not limitedto, autograft skin (i.e., skin is harvested from a patient,functionalized as described herein, and returned to the patient),organotypically cultured human skin equivalents, and other keratinocyteproducts such as Dermagraft™.

B. Polymer Multilayers Associated with Microscale or Nanoscale Beads

In some embodiments, the present invention provides polymer multilayersthat comprise nano- or microscale particles. In some embodiments, theparticles are dispersed in the polymer multilayer, for example, inbetween the polymer layers. In other embodiments, the particles aredisplayed on a surface, such as a top or a bottom surface, of thepolymer multilayer. In some embodiments, the particles are associatedwith said polymer multilayer in a manner selected from the groupconsisting of interspersed or dispersed in said polymer multilayer;displayed on a surface of said polymer multilayer; and underneath thepolymer multilayer.

In some embodiments, the polymer multilayers are formed as describedabove. In some preferred embodiments, the particles have diameter orother linear measurement of a feature, such as a length or width, whichis greater than the thickness of polymer multilayer. In someembodiments, the diameter or other linear measurement is from about 1,1.5, 2, 3, or 4 times greater than the thickness of the polymermultilayer up to about 5, 10 or 20 times greater than thickness of thepolymer multilayer.

In some embodiments, nanometer to micrometer sized biocompatibleparticles, such as spherical (e.g., beads) and/or non-spherical (e.g.,oblongs, needles, cubes, tetrahedral, mushroom-like structures,haybale-like structures) particles or electrospun polymers, are utilizedin or on the polymer multilayer. Microbeads have a size generallyranging from about 1 to about 500 micrometers, while nanobeads have asize generally ranging from about 1 to about 1000 nanometers. Microbeadsmay further comprise micro- (i.e., from 1 to 100 micrometers) ornano-scale (0.1 to 1000 nanometer) features on the surface of the bead.Nanobeads may further comprise nanoscale features (i.e., 0.1 to 500nanometer features) on the surface of the bead. In some embodiments, awound active agent is present in the form of a bead or particle, such assilver nanoparticles. In some embodiments, the biocompatible particlesare biodegradable. In some embodiments, the biocompatible particles, forexample, are modified with surface chemistry cross-linkers that allowattachment and immobilization of wound active agents, extracellularmatrix compounds, etc. as described elsewhere herein. In someembodiments, the size of the biocompatible particles, such as beads, areat least 1 nm, at least 5 nm, at least 10 nm, at least 20 nm, at least50 nm, at least 100 nm, at least 200 nm, at least 300 nm, at least 500nm, or at least 800 nm in diameter. In some embodiments, beads and otherspherical and non-spherical particles contain their own surfacetopography. For example, the bead surface may comprise undulations,indentations, tunnels, holes, knobs, ridges, etc. Spherical particles,such as beads, may or may not be inert and may, for example, bemagnetic. Magnetic beads comprise, for example, a magnetic core ormagnetic particles. Examples of different bead compositions are foundat, for example, U.S. Pat. Nos. 5,268,178, 6,458,858, 6,869,858, and5,834,121, each of which is incorporated herein by reference in itsentirety. In some embodiments, the particles comprise or are impregnatedwith a wound active agent.

It is contemplated that polymer multilayers such as those describedabove offer the opportunity to chemically and topographically engineerthe surface of substrates. Using existing technologies, one has toconstruct nanostructures or organic films (like polymer-multilayers)onto those surfaces, and dope them with active agents. Since theseprocedures are laborious (it can take 6 hrs to fabricate a multilayerfilms containing 20 layers, which is prohibitively long for saytreatment of a wound), can involve harsh chemicals, solutions havingnon-physiological pHs, and possible mechanical shear forces, they maydamage or compromise the substrates on which they are formed(particularly biological tissues and sensitive biomedical devices). Toovercome these limitations, in some embodiments, the polymer multilayersof the present invention are pre-fabricated on elastomeric stamps (suchas PDMS stamps) and then mechanically transferred to a substrate ofinterest by stamping onto the substrates of interest. Although theconcept of contact printing pre-fabricated nano and microstructures onhard substrates (microscope slides, silicon wafers) has been employedfor microfabrication of electromechanical systems; those methods failwhen used on soft substrates, particularly substrates with mechanicalproperties typically of a range of biological tissues.

The present invention provides methods and compositions of matter thatmake possible the transfer of organic and inorganic thin films,including polymer multilayers, onto compliant substrates, includingsoft-substrates with mechanical properties equivalent to those ofbiological tissues (elastic modulus, E′, of about 1-500 kPa, preferablyabout 10-100 kPa). Existing methods described in literature which allowtransfer of organic thin films onto rigid substrates like glass (E′˜65GPa) with various surface chemistries, fail when used on soft-surfaces(E′˜100 kPa). FIG. 11 demonstrates these observations. The methoddemonstrated in Example 14 and FIG. 12 facilitates transfer ofpolymer-multilayers onto soft-surfaces, including biological tissues,including skin-grafts and mouse pelts. Incorporation ofpolymer-microspheres (E′˜3 GPa) within an assembly ofpolymer-multilayers on an elastomeric stamp, when stamped onto a humanskin-graft or a biomedical grade soft silicone elastomer (E′˜100 kPa),leads to a substantially complete transfer of rigid-microspheres andpolymer-multilayers in contact with the microspheres.

This method allows engineering the surface of soft-substrates (E′˜100kPa) by contact printing pre-fabricated functionalizedpolymer-multilayers onto their surface. This opens up a vast area ofopportunities to chemically and topographically modify surfaces ofbiological tissues and soft implantable biomedical devices, likebiomedical grade silicone, and generate surfaces with tailoredfunctionality, chemistry and topography at nanometer scale. This is aversatile solution to engineer or pattern, for example, a wound-bed,from two perspectives. First, from a product development view-point,fabrication and functionalization of polymer multilayers used in thisapproach can be easily automated in a manufacturing environment usingrobots. Second, from application view-point, an end-user would simplyhave to contact-print materials from the stamps onto the substrates,instead of preparing multilayers on the substrates.

Accordingly, the present invention provides methods to tailor thesurface chemistry and nanostructured topography of soft-substrates bymechanical transfer of pre-fabricated, nanometer-thick organic films,impregnated with active agents, onto the substrates. This technologyprovides unprecedented advantages over several competing existingtechnologies. First, technology described in past literature forstamping pre-fabricated polymer-multilayer films onto substratesrelevant for the microfabrication of electromechanical systems does notallow their transfer onto soft-substrates with mechanical strengthrelevant to biological tissues. Thus, the present invention opens up thepossibilities of engineering surfaces of a whole new vast arena of softsubstrates by contact-printing pre-fabricated functionalizedpolymer-films. Some of such soft-substrates relevant for immediatecommercialization of this technology include biological tissues,wound-beds, and implantable biomedical devices like biomedical gradesilicone. Furthermore, the study performed during this invention leadsto the new observation that mechanical properties of the substratesinfluence the mechanical transfer of organic films onto them—these newprinciples of mechanical transfer can be used to selective transferorganic films on substrates with, for example, patterned soft and hardregions.

Second, to chemically or topographically modify the surface ofsoft-substrates (E′˜100 kPa) using existing technologies, one has toconstruct nanostructures or organic films (like polymer-multilayers)onto those surfaces, and dope them with active agents. Since theseprocedures mostly involve harsh chemicals, solutions atnon-physiological pHs, and possible mechanical shear forces, they maydisrupt the sensitive-substrates, particularly biological tissues andsensitive biomedical devices. The invention described here allows tocontact-print pre-fabricated polymer-multilayers impregnated with activeagents onto the soft-substrates, instead of assembling them on thosesubstrates. Furthermore, the direct stamping of pre-fabricatedpolymer-multilayers onto the substrates provide precise control over thetwo and three-dimensional placement of the polymer-multilayers. Bysequential stamping of multiple, pre-fabricated polymer-multilayersusing the methodology, multilevel and multi-component pattern structurescan be conveniently introduced onto device surfaces. Thus, thisinvention provides unprecedented control at nanometers-level over thesurface-modification of soft-substrates.

Third, in the context of wound-healing, current clinicalwound-management approaches involve delivering active agents to thewounds in ointments or dressings. The wound-dressings are reservoirs ofactive agents and require high loading concentrations for the activeagents to diffuse through the wound-fluid and reach the wound-bed whereactivity is required. High concentrations of active agents arecytotoxic, causing tissue toxicity and impaired wound-healing.

The present invention allows immobilizing active agents onto the surfaceof the wound-beds by stamping pre-fabricated nanostructuredpolymer-multilayers impregnated with active agents. Such immobilizationof active agents in polymer-multilayers over wound-bed permits: 1)Precise delivery and minimal loading of active molecules onto thewound-bed, thereby providing efficacious wound treatment withoutcytotoxic effects and at reduced costs. 2) Prolong bioavailability ofthe active agents in the wound-bed, circumventing frequent dressings andthus reducing patient pain and overall costs of wound-management. Thisis particularly significant in the treatment of chronic wounds that takeseveral months to heal. 3) Controlled delivery of bioactive molecules,both spatially and temporally. This allows regulating the distributionof active molecules across the wound-bed and creating their gradients.For example, in vitro studies have shown that gradients ofgrowth-factors promote the migration of cells involved in wound-healingto the wound-bed and can expedite wound-closure. 4) Putting activemolecules directly into the cellular microenvironment, increasing theirlocal concentration and avoiding problems of mass transfer limitationsor complex aggregation encountered in release systems. 5) Maintainingthe active molecules locally in the matrix, limiting any systemic lossor potential undesirable diffusion to distant sites.

This approach to wound-healing using current invention is fundamentallynew in the sense that it attempts to ‘engineer the wound-bed’. Thewound-bed surface is modified chemically and topographically usingnanometer-thick organic films impregnated with minimal concentrations ofactive agents. This contrasts to currently practiced approaches whichattempt to treat the wound by drizzling high concentrations of bioactiveagents over the wound.

Accordingly, in some embodiments, the present invention provides apolymer multilayer comprising at least one polymer, the polymermultilayer having associated therewith particles selected from the groupconsisting of nanoscale and microscale particles. In some embodiments,the polymer multilayer is from 1 nm to 1000 nm thick and in preferredembodiments, from about 1 to about 250 nm thick. In some embodiments,the polymer multilayer has a compliance of from 3 to 500 kPa. In someembodiments, the polymer multilayer is disposed on a support. In someembodiments, the polymer multilayer is formed on a support. In somepreferred embodiments, the support is an elastomeric support.

In some embodiments, the present invention provides methods formodifying a surface comprising contacting a surface with a polymermultilayer as described above under conditions such that said polymermultilayer is transferred to said surface. In some embodiments, thesurface is a soft surface. In some embodiments, the surface has anelastic modulus of from about 1 to about 500 kPa, preferably about 10 toabout 100 kPa. In some embodiments, the surface is a biological surface.In some embodiments, the biological surface comprises proteins, lipidsand/or carbohydrates. In some embodiments, the biological surface isselected from the group consisting of skin, a wound bed, hair, a tissuesurface, and an organ surface. In some embodiments, the surface is abiologically compatible surface, or the surface of a biomedical device.In some embodiments, the surface is a silicone surface.

C. Functionalization Agents

In some embodiments, the matrices described above are functionalized. Inpreferred embodiments, the matrices are functionalized with one or morecovalent modification agents. In some preferred embodiments, thecrosslinkers comprise either an azide group or an alkyne group so thatsuitable click chemistries can be utilized. In some embodiments, the atleast one covalent modification agent is a homobifunctionalcross-linker. In other embodiments, the at least one covalentmodification agent is a heterobifunctional cross-linker. For example, insome embodiments, the homobifunctional cross-linker is anN-hydroxysuccinimidyl ester (e.g., including, but not limited to,disuccinimidyl ester, dithiobis(succinimidylpropionate),3,3′-dithiobis(sulfosuccinimidylpropionate), disuccinimidyl suberate,bis(sulfosuccinimidyl)suberate, disuccinimidyl tartarate,disulfosuccinimidyl tartarate,bis[2-(succinimidyloxycarbonyloxy)ethyl]sulfone,bis[2-(sulfosuccinimidooxycarbonyloxy)ethyl]sulfone, ethyleneglycolbis(succinimidylsuccinate), ethyleneglycolbis(sulfosuccinimidylsuccinate), disuccinimidyl glutarate, andN,N′-disuccinimidylcarbonate). In some embodiments, the homobifunctionalcross-linker is at a concentration between 1 nanomolar and 10millimolar. In some preferred embodiments, the homobifunctionalcross-linker is at a concentration between 10 micromolar and 1millimolar. In other embodiments, the at least one covalent modificationagent is a heterobifunctional cross-linker (e.g., including, but notlimited to, N-succinimidyl 3-(2-pyridyldithio)propionate, succinimidyl6-(3-[2-pyridyldithio]-propionamido)hexanoate, sulfosuccinimidyl6-(3′-[2-pyridyldithio]-propionamido)hexanoate,succinimidyloxycarbonyl-α-methyl-α-(2-pyridyldithio)toluene,sulfosuccinimidyl-6-[α-methyl-α-(2-pyridyldithio)toluamido]hexanoate,succinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate,sulfosuccinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate,m-maleimidobenzoyl-N-hydroxysuccinimide ester,m-maleimidobenzoyl-N-hydroxy-sulfosuccinimide ester,N-succinimidyl(4-iodoacetyl)aminobenzoate,sulfo-succinimidyl(4-iodoacetyl)aminobenzoate,succinimidyl-4-(p-maleimidophenyl)butyrate,sulfosuccinimidyl-4-(p-maleimidophenyl)butyrate,N-(γ-maleimidobutyryloxy)succinimide ester,N-(γ-maleimidobutyryloxy)sulfosuccinimide ester, succinimidyl6-((iodoacetyl)amino)hexanoate, succinimidyl6-(6-((((4-iodoacetyl)amino)hexanoyl)amino)hexanoate, succinimidyl4-(((iodoacetyl)amino)methyl)cyclohexane-1-carboxylate, succinimidyl6-((((4-iodoacetyl)amino)methyl)cyclohexane-1-carbonyl)amino)-hexanoate,and p-nitrophenyl iodoacetate). In some embodiments, theheterobifunctional cross-linker is modified with functional groups,rendering it soluble in aqueous solvents for delivery as an aqueoussolution. Furthermore, in some embodiments, the aqueous solutioncontains additives (e.g., including, but not limited to, surfactants andblock copolymers). In other embodiments, a multiplicity ofhetero-bifunctional cross-linkers can be attached to a molecule, polymeror particle to serve as the cross-linking agent. In other embodiments,the heterobifunctional cross-linker is dissolved in an organic solvent(e.g., including, but not limited to, dimethyl sulfoxide).

In some embodiments, the covalent modifier is a photoactivatablecrosslinker. Suitable photoactivatable crosslinkers include, but are notlimited to, aryl azide N-((2-pyridyldithio)ethyl)-4-azidosalicylamide,4-azido-2,3,5,6-tetrafluorobenzoic acid, succinimidyl ester,4-azido-2,3,5,6-tetrafluorobenzoic acid, STP ester, benzophenonemaleimide, succinimidyl ester of 4-benzoylbenzoic acid,N-5-Azido-2-Nitrobenzoyloxysuccinimide,N-Hydroxysulfosuccinimidyl-4-azidobenzoate,N-Hydroxysuccinimidyl-4-azidosalicylic acid, and(4-[p-Azidosalicylamido]butylamine).

The covalent modification agent may be applied to the matrix by anysuitable method. In some embodiments, it is contemplated that thecovalent modification agent is applied using either a pump (includingsyringes, ink jet printers, and electrojets) or spray, such as anaerosol spray. In other embodiments, the use of a brush including an airbrush is contemplated. In other embodiments, a sponge is utilized.

Following application of the covalent modification agent to the matrix,a functionalized matrix is formed. In some embodiments, thefunctionalized matrix displays one or more reactive moieties, forexample, azide moieties, succinimidyl moieties, alkyne moieties or anyof the other reactive groups of the compounds described above.

In some embodiments, the matrix is modified by PEGylation withpolyethylene glycol. It is contemplated that PEGylation can be used tocontrol interaction of the matrix with the wound bed and to preventnonspecific adsorption as desired. PEGylation can also be used tocontrol delivery of the wound active agent from the matrix.

D. Wound Active Agents

In some embodiments, the matrices comprise one or more wound activeagents as described in detail above. In some embodiments, the woundactive agent or agents are noncovalently incorporated into the matrix.In some preferred embodiments, silver containing antimicrobials areincorporated into the functionalized matrix, for example, apolyelectrolyte multilayer as described above. In some embodiments, thewound active agent or agents are covalently immobilized on the matrix,for example, via a covalent modification agent.

In some embodiments, the one or more wound active agents are applied toform a gradient with respect to the wound modifying agent. In general,the gradients present a higher contraction of wound active agent at oneor more first desired locations in the wound following application ofthe wound modifying agent to the wound and a lower concentration ofwound active agent at one or second location in the wound followingapplication of the matrix to the wound. For example, the concentrationsof the wound active agents are layered in a wound bed in a gradient suchthat higher concentrations of a particular composition is greaterproximal to the wound bed than distal to the wound bed in a verticalfashion. The converse, where concentrations of compositions is greaterdistal to the wound bed than proximal, is also contemplated.Concentration of compositions in a wound bed wherein a horizontalgradient is deposited is also contemplated. Topographical gradients arealso contemplated, wherein compositions are deposited such that theconcentrations of compositions in a wound bed or on a biocompatibleparticle follow the topography of the substrate, for example, a higherconcentration of compositions is deposited in the valleys of undulationsof an exemplary substrate compared to the peaks of the undulations.

In some embodiments, the gradient comprises a higher concentration ofthe wound active agent in the center of the matrix which transitions toa lower concentration of the wound active agent away from the center ofthe matrix. Accordingly, when the matrix is applied to a wound, thegradient results in a higher concentration of wound active agent in thecenter of the wound and a lower concentration of wound active agent asone moves to the periphery of the wound. In some embodiments, thegradient comprises a lower concentration of the wound active agent inthe center of the matrix which transitions to a higher concentration ofthe wound active agent away from the center of the matrix. Accordingly,the gradient results in a lower concentration of wound active agent inthe center of the wound and a higher concentration of wound active agentas one moves to the periphery of the wound. If two or more wound activeagents are utilized, they can be presented as similar gradients or thegradients can be varied so that the concentrations of the two or morewound active agents vary across the wound. The gradients of high or lowconcentration can be any shape, such as circular, square, rectangular,oval, oblong, etc. so that the matrix and gradient can conform to avariety of wound shapes. For example, for long, incision type wound, thegradient may be centered on a longitudinal axis that extends along thelength of the wound and can be centered on the wound. As anotherexample, the gradient can be circular or oval-shaped for application toopen type wounds, burns, sores and ulcers that are roughly circular oroval. In other embodiments, the gradients comprise a series of featuresarranged in a pattern. For example, the gradients can form a series ofstripes or high and low concentrations of one or more wound activeagents along a longitudinal axis of the matrix. Alternatively, thegradients can form a checkerboard pattern, array, concentric circles,overlapping circles or oval, etc.

E. Support Materials

In some embodiments, the matrices are formed on a support material.Suitable support materials include, but not limited to, solid supportsformed from polymeric materials, elastomeric materials such PDMS, nylon,Teflon®, Gortex®, silk, polyurethane, and silicon, preferably medicalgrade silicon, PVDF, polyethylene oxide, and water soluble materials andpolymers such as polyvinyl alcohol. In some embodiments, the polymer(s)used to form the polymer multilayer are different than the polymer(s)forming the support. In some embodiments, an additional layer ofmaterial, such as a water soluble material or polymer, is disposedbetween the polymer multilayer and the support. In some embodiments, thesolid support is a wound dressing or biologic wound dressing that iscompatible with functionalization by addition of a matrix material.Examples of commercially available wound dressings that can be modifiedby addition of a matrix as described below include, but are not limitedto, Biobrane™, gauze, adhesive tape, bandages such as BandAids®, andother commercially available wound dressings including but not limitedto COMPEEL®, DUODERM™, TAGADERM™ and OPSITE®. In some embodiments, thesupport is a silicon wafer, surfaces, such as glass or silicon wafers,that are coated with hydrophobic self assembled monolayer, fabrics, suchas nylon fabrics, absorbent material, foam, a transparent thin film, ahydrogel, hydrofibers, hydrocolloids, alginate fibers, silica gel,sodium polyacrylate, potassium polyacrylamides and combinations thereof.In some embodiments, the supports comprise (e.g., is coated with ordisplays) a biological molecule selected from the group consisting ofcollagen, hyaluronic acid, glycosaminoglycans, keratin, fibronectin,vitronectin, laminin, and combinations or fragments thereof.

The matrices described above can be synthesized directly on the supportmaterial or transferred to the support material following synthesis, forexample by transfer or stamping from a suitable support, such as anelastomeric support. There are several different methods that can beused to deposit polymer multilayers on a support. In some embodiments,the polymer multilayers are deposited onto a support by adsorption fromsolution, spraying, or spin coating. As described above, the matricesare preferably polymer multilayers, for example, polyelectrolytemultilayers. In some embodiments, the matrices preferably comprise onemore wound active agents as described above and/or or nanoscale ormicroscale beads as described above. In some preferred embodiments, thewound active agent is one or more of silver nanoparticles, elementalsilver, and silver containing compounds such as silver sulfadiazine andrelated compounds, preferably included in the concentration rangesdescribed above.

In some embodiments, the present invention provides methods fortransferring a polymer multilayer to a desired surface, such as softsurface. Such soft surfaces include, but are not limited to, skin, awound bed, a tissue, artificial tissues including artificial skintissues such as organotypically cultured skin tissues, Apligraf®,Dermagraft®, Oasis®, Transcyte®, Cryoskin® and Myskin®, artificialtissue matrices, gels comprising biomolecules, a wound dressing, and abiologic wound dressing. In some embodiments, the desired surface iscontacted with a polymer multilayer, e.g., a polymer multilayersupported on a support and pressure is applied to effect transfer of thepolymer multilayer from the support to the desired surface. In someembodiments, the pressure is from about 10 to about 500 kPa. In someembodiments, the transfer is performed in the substantial, or complete,absence of solution. Such dry transfer processes do not involve exposureof biological components of the desired surface to aqueous solutionscontaining species that may influence the activity of the biologicalcomponents. In some embodiments, the transfer is performed through a gasphase. In some embodiments, the transfer is performed in an environmentwhere the humidity is less than 100% of saturation. In some embodiments,the transfer is performed in the absence of liquid water.

Accordingly, in some embodiments, the present invention provides wounddressings comprising a support material having a surface oriented to awound, wherein the surface oriented to the wound is modified with amatrix material of the present invention. When applied to a wound, thesurface of the support material modified with the matrix material is putinto contact with the wound bed.

In some embodiments, the support is a biologic wound dressing. In someembodiments, the biologic wound dressing is a type of wound dressingthat comprises, e.g., is coated with or incorporates, cells (e.g.,keratinocytes or fibroblasts and combinations thereof) and/or one ormore biomolecules or fragments of biomolecules that can be placed incontact with the wound surface. The biomolecules may be provided in theform of an artificial tissue matrix omprising one or more biomolecules.Examples of such biomolecules include, but are not limited, to collagen,glycosaminoglycans, hyaluronic acid, laminin, vitronectin, fibronectin,keratin, antimicrobial polypeptides and combinations thereof. Examplesof suitable biologic wound dressings include, but are not limited to,BIOBRANE™, Integra™, Apligraf®, Dermagraft®, Oasis®, Transcyte®,Cryoskin® and Myskin®.

In some embodiments, the support material is a biosynthetic wounddressing constructed of an elastomeric film (e.g., a silicone film)supported on support material, such as a fabric, preferably a polymericfabric such as a nylon fabric. In some embodiments, the fabric is atleast partially imbedded into the film (e.g., BioBrane™). In someembodiments, the elastomeric film is coated with one or morebiomaterials, for example collagen, keratin, fibronectin, vitronectin,laminin and combinations thereof. Accordingly, the fabric presents tothe wound bed a complex 3-D structure to which a biomaterial (e.g.,collagen) has been bound, preferably chemically bound. In some preferredembodiments, the surface presented to the wound is further modified witha matrix material as described above. In some preferred embodiments, thematrix material is a polyelectrolyte membrane comprising a wound activeagent, preferably selected from one or more of silver nanoparticles,elemental silver, and silver containing compounds such as silversulfadiazine and related compounds, and preferably included in theconcentration ranges described above. In some embodiments, the matrixfurther comprises nanoscale or microscale particles. The matrix can besynthesized directly on the collagen modified surface or transferred tothe collagen modified surface by stamping as described above.

In some embodiments, the support material is an adhesive bandagecomprising an adhesive portion (such as an adhesive strip) and anabsorbent material, preferably treated or coated with a material (i.e.,a non-adherent material) to prevent adhesion to the wound or comprisinga layer of non-adherent material, such as Teflon®, on the surface of theabsorbent pad that will contact the wound. In some embodiments, thesupport material is an absorbent pad (e.g., a gauze pad or polymer foam)preferably treated or coated with a material (i.e., a non-adherentmaterial) to prevent adhesion to the wound or comprising a layer ofnon-adherent material, such as Teflon® or other suitable material, onthe surface of the absorbent pad that will contact the wound. In someembodiments, the non-adhesive material or layer is breathable. In someembodiments, the wound dressing comprises a gel-forming agent, forexample, a hydrocolloid such as sodium carboxymethylcellulose. In someembodiments, the absorbent pads or gel-forming agents are affixed to amaterial that is waterproof and/or breathable. Examples include, but arenot limited, semipermeable polyurethane films. The waterproof and/orbreathable material may further comprise an adhesive material forsecuring the bandage to the skin of a subject. The waterproof and/orbreathable material preferably forms the outer surface of the adhesivebandage or pad, i.e., is the surface opposite of the surface comprisingthe matrix which contacts the wound. Examples of such adhesive bandagesand absorbent pads include, but are not limited to, to adhesive bandagesand pads from the Band-Aid® line of wound dressings, adhesive bandagesand pads from the Nexcare® line of wound dressings, adhesive bandagesand non-adhesive pads from the Kendall Curity Tefla® line of wounddressings, adhesive bandages and pads from the Tegaderm® line of wounddressings, adhesive bandages and pads from the Steri-Strip® line ofwound dressings, the COMFEEL® line of wound dressings, adhesive bandagesand pads, the Duoderm® line of wound dressings, adhesive bandages andpads, the TEGADERM™ line of wound dressings, adhesive bandages and pads,the OPSITE® line of wound dressings, adhesive bandages and pads,adhesive bandages and pads from the Allevyn™ line of wound dressings,adhesive bandages and pads from the Duoderm® line of wound dressings,and adhesive bandages and pads from the Xeroform® line of wounddressings.

In some embodiments, the present invention provides methods and systemsfor producing the articles described above. In some embodiments, thepolyelectrolyte multilayers are directly deposited on the solid supportby any of the methods described in detail above. In some embodiments,the polyelectrolyte multilayers are deposited onto a stamp material,such as PDMS, and then transferred to the solid support by a stampingprocess as described in detail above.

F. Use of Matrices

In some embodiments, a matrix as described above is applied to a woundunder conditions such that wound healing, as measured by woundcontraction, is accelerated. In some embodiments, the matrix isfunctionalized just prior to application to a wound, while in otherembodiments, the matrix is provided in a sterile package and isfunctionalized so that it is ready for application following removalfrom the sterile packaging. In some embodiments, the wound is pretreatedor primed with a covalent modification agent that is reactive with thefunctionalization agent displayed by the functionalized matrix. Forexample, the wound may be modified as described in detail above with acovalent modification agent displaying a reactive azide group, while thematrix may be modified with a covalent modification agent displaying analkyne group. In general, the wound may be modified with covalentmodification agent A which displays reactive group X and the matrixdisplays covalent modification agent B which displays reactive group Y,wherein X and Y react with each other to form a covalent bond.

In some embodiments, the matrices are provided as kits, preferably withthe matrix in a sterile package. In some embodiments, the matrix in thekit is pre-functionalized, while in other embodiments, the matrix is notfunctionalized and the kit comprises at least one functionalizationagent along with instructions on how to functionalize the matrix. Insome embodiments, the kits comprise a functionalization agent forfunctionalizing the wound bed prior to application of the matrix. Insome embodiments the matrix providing in the kit comprises at least onewound active agent. In other embodiments, the kits comprise a woundactive agent and instructions from applying the wound active agent tothe matrix prior to application to a wound.

IV. Methods of Treating Wounds

A wound modifying agent with one or more wound active agents or matrix,as described above can be applied to all types of wounds. Furthermore,the compositions of the present invention can be applied to all types ofwounds. Furthermore, a wound modifying agent with one or more woundactive agents can be applied to skin, mucous membranes, body cavities,and to internal surfaces of bones, tissues, etc. that have been damaged.A wound modifying agent with one or more wound active agents can be usedon wounds such as cuts, abrasions, ulcers, surgical incision sites,burns, and to treat other types of tissue damage. In some embodiments ofthe present invention, the compositions and methods described aboveenhance wound healing. The present invention contemplates that woundhealing may be enhanced in a variety of ways. In some embodiments, thecompositions and methods minimize contracture of the wound as to bestfavor function and cosmesis. In some embodiments, compositions andmethods promote wound contracture to best favor function and cosmesis.In some embodiments, the compositions and methods promotevascularization. In some embodiments, the compositions and methodsinhibit vascularization. In some embodiments, the compositions andmethods promote fibrosis. In some embodiments, the compositions andmethods inhibit fibrosis. In some embodiments, the compositions andmethods promote epithelial coverage. In some embodiments, thecompositions and methods inhibit epithelial coverage. In someembodiments, the compositions and methods of the present inventionmodulates one or properties of cells in the wound environment or in theimmediate vicinity of the wound. The properties that are modulated,e.g., are increased or decreased, include, but are not limited toadhesion, migration, proliferation, differentiation, extracellularmatrix secretion, phagocytosis, MMP activity, contraction, andcombinations thereof.

The compositions of the present invention can be covered with asecondary dressing, or bandage, if desired to protect the layer or toprovide additional moisture absorption, for example.

If desirable, the wound modifying agent with one or more wound activeagents can be reapplied at a later time. It may be desirable to woundmodifying agents having different formulations of wound active agents atdifferent stages of wound healing.

In some embodiments, the immobilization of cytoactive factors andmatrices immobilized on a wound bed using, for example, polyelectrolytesare evaluated in vitro and in vivo. In some embodiments, in vitroanalysis comprising studying the ability of cytoactive factors toproliferate cell growth is evaluated in corneal epithelial cells andhuman vascular endothelial cells. In some embodiments, in vitro analysiscomprises the construction of synthetic surfaces that mimic a wound bed,wherein said surfaces are created to comprise surface chemistries suchas primary amine groups, carboxylic acids and thiol groups that arerepresentative of the diversity of chemical functionality present in awound bed. For example, ECM constituents and cytoactive factors areapplied to the synthetic surfaces, and immobilization is confirmed by,for example, fluorescently labeled antibodies to the ECMs and cytoactivefactors thereby immobilized. Further in vitro analysis includes, but isnot limited to, proliferation dose response of the cytoactive factorsand EMCs on the synthetic surfaces. In some embodiments, the in vitroassays are used to evaluate cytoactive factors that inhibit specificcell growth in a wound bed, thereby allowing for preferentialrecruitment and growth of those cell types optimal for wound healing andrapid return of tissue function and non-recruitment of antagonistic cellspecies.

In one embodiment, assays to evaluate immobilization strategies areperformed ex vivo. In some embodiments, cutaneous wounds are harvestedfrom mice. For example, a 6 mm surgical skin punch is used to create acutaneous defect post-mortem, followed by removal of the entire woundbed (e.g., with underlying stromal muscular elements). Similar to themodel in vitro system as previously described, the ex vivo model systemincludes linker chemistries and the like, and the immobilizationstrategies are evaluated, for example, using fluorescently labelledproteins. In some embodiments, the ex vivo model system comprises theimmobilization of biotinylated BSA. In some embodiments, the surface ofthe wound bed is activated with a NHS ester by exposure to, for example,1 mM BS₃. Biotinylated BSA (at, for example, 2 mg/ml) is subsequentlyadded to the activated wound bed and allowed to attach for 2 hours. Thebiotinylated BSA immobilization is determined by FITC-labeledanti-biotin antibody. As such, once immobilization is verified (viafluorescence detection), evaluation of optimal chemical functionalitiesis determined for wound bed immobilization. For example, chemicalfunctionalities are determined by replacing BS₃ in the ex vivo modelsystem with heterobifunctional cross-linkers as described herein thatreact with, for example, carboxylic acids, amines, and thiol groupsfound in the wound bed. Further, upon determination of optimalcross-linkers, the immobilization of cytoactive agents and extracellularmatrix compounds as described herein are evaluated (e.g., usingfluorescently labeled antibodies to immobilized compounds). It iscontemplated that key parameters to a successful ex vivo evaluationinclude, but are not limited to, concentration of all immobilizationcompositions, buffer systems, and incubation times. Ex vivo evaluationsconstitute additional validation of in vivo wound bed healing systems.

In one embodiment, in vivo experiments further validate the wound bedhealing methods as described herein. In some embodiments, the diabetictransgenic mouse db/db are used, as a phenotype of the diabetic mice isimpaired wound healing. Polyelectrolytes, cytoactive agents, andextracellular matrices as described herein are applied to the db/db micefor optimization of wound healing. The present invention is not limitedto a particular mechanism. Indeed, an understanding of the mechanism isnot necessary to practice the present invention. Nonetheless, it iscontemplated that optimized wound healing in diabetic mice provides amodel system that correlates to wound healing for normal, cutaneouswounds. In one example, skin wounds are created in tandem on diabeticmice using a surgical skin punch. After wounding, test compounds areimmobilized in one of the wounds, leaving the other as a control (e.g.,BSA only). The test compounds are evaluated, for example as described inExample 3, thereby providing further information for useful in vivocompositions for wound bed healing. Information on the impact of thetest compounds on wound healing is also obtained by, for example,evaluation of the wound bed for epithelial coverage, extent of formationof granulation tissue, collagen content, inflammation, fibroblastpopulation and vascularization. Test compounds include, but are notlimited to, the polyelectrolytes as described herein, extracellularmatrix components (e.g., collagen, laminin, MATRIGEL, fibronectin, etc.)and cytoactive agents (e.g., EGF, VEGF, PDGF). To further characterizethe wound bed, confocal microscopy is used to visualize cellularcomponents in a three-dimensional space, thereby allowing for thevisualization of the wound bed treatments in a native state.

In some embodiments, the present invention provides for the developmentof personalized therapeutic protocols for wound healing. For example,the compositions as described herein for wound healing are adapted foreach individual wound, taking into account, for example, environmentalfactors, incubation times, application dynamics, wound bed structure,associated disease state (e.g., diabetes, etc.) and the like that makeeach wound bed unique. As such, the present invention provides for thealteration of surface chemistry/structure for each unique wound bed,using the compositions and methods as described herein.

EXPERIMENTAL

The examples below serve to further illustrate the invention, to providethose of ordinary skill in the art with a complete disclosure anddescription of how the compounds, compositions, articles, devices,and/or methods claimed herein are made and evaluated, and are notintended to limit the scope of the invention. The examples are notintended to restrict the scope of the invention.

Example 1 Covalent Immobilization of a Protein to a Surface

To demonstrate that proteins can be covalently immobilized on modelsurfaces, bovine serum albumin (BSA) was used as the protein in themodel system. Bovine serum albumin was biotinylated (BSA used ascontrol) and covalently attached to gamma-amino propyl silanes(GAPS)-treated glass surfaces using the homobifunctional bifunctionalcross-linker BS₃ (1 mM for 15 min.). BS₃ contains an amine-reactiveN-hydroxysulfosuccinimide (NHS) ester at each end of an 8-carbon spacerarm. The NHS esters react with primary amines at pH 7-9 to form stableamide bonds, along with release of the N-hydroxysulfosuccinimide leavinggroup. For detection purposes, the biotinylated BSA was labeled withFITC-labeled anti-biotin antibodies and the BSA control was probed usingFITC-antigoat antibodies.

The large fluorescent signal seen in FIG. 3 from the surfaces treatedwith biotinylated BSA and FITC-antibiotin antibody (diamonds) relativeto controls (vertical lines, diagonal lines, bricks) confirms covalentattachment of the biotinylated BSA to the surface.

Example 2 Layer by Layer Deposition of Polyelectrolytes in Ex Vivo WoundBeds

Experiments depositing polyelectrolytes in wound bed explants from micewere performed. Cutaneous wounds from euthanized mice were harvested.The excised wounds were sequentially treated with aqueous solutions(0.5M NaCl, PBS at pH 7.0) containing polystyrene sulfonate (PSS, 1mg/ml) and FITC-labeled poly allylamine hydrochloride (FITC-PAH, 1mg/ml). Between adsorption steps, the wounds were treated rinsed withPBS. After each treatment with FITC-PAH, the intensity of fluorescencewas recorded. As seen in FIG. 4, the growth in fluorescence after eachtreatment cycle with PSS and FITC-PAH demonstrates growth of amultilayered polyelectrolyte film on the wound bed, relative to controltreatments.

Example 3 Use of Mesoscopic Cross-Linkers in Ex Vivo Wound Beds

Skin wounds are created in tandem on diabetic mice using a surgical skinpunch. After wounding, one of the wounds is treated by contact withactivated 10-micrometer diameter polystyrene beads with surfacesterminated in carboxylic acid groups. The activation of the carboxylicacid groups is achieved by incubation in EDC/NHS solution (200 mM/50 mM)in phosphate buffered saline (PBS) (10 mM phosphate, 120 mM NaCl, 2.7 mMKCl; pH 7.6) for 1 h at room temperature. Following activation, thebeads were pipetted into the wound beads and allowed to incubate withinthe wound beds for 1 hr. After incubation, the wound beds are washedexhaustively with PBS, and then incubated with collagen (10 micromolarin PBS). The remaining wound is used as a control and treated asdescribed above, but without activation of the beads with NHS/EDC. Thesize of the wound is measured after 2, 4, 6, 8 and 10 days. It isobserved that the treated wound decreases in size faster than thecontrol wound.

Example 4 Delivery of the Wound Modifying Agents Using Aerosol Sprays

Experiments depositing polyelectrolytes in wound bed explants from miceare performed using aerosol sprays. Cutaneous wounds from euthanizedmice are harvested. The excised wounds are sequentially treated by thespraying (using aerosol spray cans) of aqueous solutions (0.5M NaCl, PBSat pH 7.0) containing polystyrene sulfonate (PSS, 1 mg/ml) orFITC-labeled poly allylamine hydrochloride (FITC-PAH, 1 mg/ml). Betweenspraying steps, the wounds are treated rinsed with PBS. After eachtreatment with FITC-PAH, the intensity of fluorescence is recorded. Ameasurement of the growth in fluorescence after each treatment cyclewith PSS and FITC-PAH demonstrates growth of a multilayeredpolyelectrolyte film on the wound bed, relative to control treatments.

Example 5 Delivery of the Wound Modifying Agents Using Pumps

Experiments depositing polyelectrolytes in wound bed explants from miceare performed by sequentially delivering the wound healing agent to thewound beds using pumps. Cutaneous wounds from euthanized mice areharvested. A peristaltic pump (Fischer Scientific) is used to pump theliquid. The excised wounds are sequentially treated by pumping ofaqueous solutions (0.5M NaCl, PBS at pH 7.0) containing polystyrenesulfonate (PSS, 1 mg/ml) or FITC-labeled poly allylamine hydrochloride(FITC-PAH, 1 mg/ml). Between pumping steps involving thepolyelectrolytes, the wounds are treated rinsed with PBS using pumps.After each treatment with FITC-PAH, the intensity of fluorescence isrecorded. A measurement of the growth in fluorescence after eachtreatment cycle with PSS and FITC-PAH demonstrates growth of amultilayered polyelectrolyte film on the wound bed, relative to controltreatments.

Example 6 Delivery of the Wound Modifying Agents Using Stamps

Experiments depositing polyelectrolytes in wound bed explants from miceare performed by stamping of polyelectrolytes into the wound bed fromelastomeric stamps. Elastomeric stamps are prepared from PDMS usingparts A and B of a kit purchased from Dow-Corning. After curing thestamps in an oven at 100° C. for 12 hrs, the surface of the PDMS stampis incubated with aqueous solutions (0.5M NaCl, PBS at pH 7.0)containing polystyrene sulfonate (PSS, 1 mg/ml) or FITC-labeled polyallylamine hydrochloride (FITC-PAH, 1 mg/ml). Between incubation stepsinvolving the polyelectrolytes, the PDMS stamp is rinsed with PBS. After10 layers each of PSS and PAH are deposited onto the stamp, the stamp ismechanically contacted with the cutaneous wounds harvested fromeuthanized mice. After removal of the stamp from the wound bed, theintensity of fluorescence of the wound bed is recorded. A measurement ofthe fluorescence relative to control treatments (PBS free ofpolyelectrolytes is incubated with the stamps) verifies the depositionof the wound modifying agent into the wound bed.

Example 7 Delivery of the Wound Modifying Agents to Surfaces UsingInkjet Technology

To demonstrate that inkjet technology can be used to deliver woundmodifying agents to surfaces, aqueous solutions (in PBS) ofFITC-labelled collagen are inkjet printed onto gamma-amino propylsilanes (GAPS)-treated glass surfaces that are activated using thehomobifunctional bifunctional cross-linker BS₃ (1 mM for 15 min.). BS₃contains an amine-reactive N-hydroxysulfosuccinimide (NHS) ester at eachend of an 8-carbon spacer arm. The NHS esters react with primary aminesat pH 7-9 to form stable amide bonds, along with release of theN-hydroxysulfosuccinimide leaving group. The surfaces are exhaustivelywashed with PBS. The fluorescence intensity of the surface ismeasurements to indicate attachment of the FITC-labelled collagen to thesurface relative to a control experiment in which the activated surfaceis pre-exposed to BSA (1 mg/ml in PBS for 2 hrs), prior to injectprinting of the FITC-labelled collagen.

Example 8 Delivery of the Wound Modifying Agents Using Air Brushes

Experiments depositing polyelectrolytes in wound bed explants from miceare performed using airbrushes. Cutaneous wounds from euthanized miceare harvested. The excised wounds are sequentially treated by theairbrushing of aqueous solutions (0.5M NaCl, PBS at pH 7.0) containingpolystyrene sulfonate (PSS, 1 mg/ml) or FITC-labeled poly allylaminehydrochloride (FITC-PAH, 1 mg/ml). The airbrushes are prepared bypouring the aqueous polyelectrolyte solutions into the air brushes.Between brushing steps, the wounds are rinsed with PBS. After eachtreatment with FITC-PAH, the intensity of fluorescence is recorded. Ameasurement of the growth in fluorescence after each treatment cyclewith PSS and FITC-PAH demonstrates growth of a multilayeredpolyelectrolyte film on the wound bed, relative to control treatments inwhich PBS solutions free of polyelectrolytes are air brushed onto thesurfaces.

Example 9 Method to Modify the Topography of the Wound Bed

Skin wounds are created in tandem on diabetic mice using a surgical skinpunch. After wounding, one of the wounds is treated by contact with a1:1 mixture of activated 100-nanometer and 1 micrometer diameterpolystyrene beads with surfaces terminated in carboxylic acid groups.The activation of the carboxylic acid groups is achieved by incubationin EDC/NHS solution (200 mM/50 mM) in phosphate buffered saline (PBS)(10 mM phosphate, 120 mM NaCl, 2.7 mM KCl; pH 7.6) for 1 hour at roomtemperature. Following activation, the mixture of beads are pipettedinto the wound beads and allowed to incubate within the wound beds for 1hr. After incubation, the wound beds are washed exhaustively with PBS,and then incubated in albumin (10 micromolar in PBS). The remainingwound is used as a control and treated as described above, but withoutactivation of the beads with NHS/EDC. The size of the wound is measuredafter 2, 4, 6, 8 and 10 days. It is observed that the treated wounddecreases in size faster than the control wound.

Example 10 Method to Covalently Modify the Wound Bed Using a Combinationof Polyelectrolytes and Covalent Cross-Linking Agents

Skin wounds are created in tandem on diabetic mice using a surgical skinpunch. After wounding, one of the wounds is treated by contact withactivated 1-micrometer diameter polystyrene beads with surfacesterminated in carboxylic acid groups. The activation of the carboxylicacid groups is achieved by incubation in EDC/NHS solution (200 mM/50 mM)in phosphate buffered saline (PBS) (10 mM phosphate, 120 mM NaCl, 2.7 mMKCl; pH 7.6) for 1 hour at room temperature. Following activation, thebeads are pipetted into the wound beds and allowed to incubate withinthe wound beds for 1 hr. After incubation, the wound beds are washedexhaustively with PBS, and then incubated with PAH, and then washedagain in PBS. After PAH, the wound bed is sequentially treated with PSSand FITC-labelled PAH (as described above). Between each adsorptionstep, the wound bed is rinsed with PBS. Fluorescence measurements of thewound bed after each FITC-PAH adsorption step confirm immobilization ofthe PSS and PAH to the wound bed.

Example 11 Method to Modify the Mechanical Compliance of the Wound Bed

The mechanical compliance of the wound bed is modified by depositingpolyelectrolytes into the wound bed and cross-linking thepolyelectrolyte films. Experiments depositing polyelectrolytes in woundbed explants from mice are performed. Cutaneous wounds from euthanizedmice are harvested. The excised wounds are sequentially treated withaqueous solutions (0.5M NaCl, PBS at pH 7.0) containing polystyrenesulfonate (PSS, 1 mg/ml) and FITC-labeled poly allylamine hydrochloride(FITC-PAH, 1 mg/ml). Between adsorption steps, the wounds are treatedand rinsed with PBS. After treatment with the polyelectrolytes, BS3 (1mM in PBS) is added to the wound bed and incubated for 1 hr. Upon pokingwith the end of a spatula, the rigidity of the wound bed is noticeablygreater than a wound bed treated with polyelectrolytes without the finalcross-linking step. The increase in ridigidity (decreased compliance) isconfirmed by Atomic Force Microscopy.

Example 12 Method to Alter Intrinsic Compliance of Wound Bed

The mechanical compliance of the wound bed is altered by controlledapplication of enzyme(s) capable of degrading constituents of theextracellular matrix. Cutaneous wounds from euthanized mice areharvested. 10 μM concentration of collagenase is applied to the woundand allowed to incubate at room temperature for times ranging from 0min-1 hour. The wound beds are then rinsed copiously with PBS. Wet Fieldforce microscopy of the wound beds confirms that application ofdegradative enzymes increases the compliance (decreases rigidity) of thewound beds in a time dependent fashion.

Example 13 Nanometer-Thick Silver-Impregnated Polymeric Films ShowingSelective Toxicity Towards Bacterial Growth and that Support MammalianCell Growth

Polyelectrolyte multilayers electrostatically assembled alternately fromsuch weak polyacids as poly(allylamine hydrochloride) (PAH) andpoly(acrylic acid) (PAA) were tuned to impregnate post-assembly withsilver nanoparticles to levels where they kill bacteria effectively yetallow adhesion of mammalian cells on the films without measurablecytotoxicity. Silver ions (Ag⁺) were incorporated in the films byincubating them with bulk solution of a silver salt (e.g., silvernitrate). While the present invention is not limited to any particularmechanism, and an understanding of the mechanism is not necessary topractice the present invention, it is contemplated that Ag⁺ ions boundto the free carboxylic acid groups of PAA in the films by ion exchangewith the acidic protons. Post binding, Ag⁺ in the films were reduced tozerovalent Ag nanoparticles by using an aqueous solution of a reducingagent. By changing the pH of the polyelectrolyte assembly solutions, thenumber of non-ionized carboxylic acid groups (and hence the amount ofsilver incorporated) in the PEMs post-assembly was effectivelycontrolled. These silver-impregnated nanometer-thick films were theninvestigated for their interactions with NIH-3T3 cells, a highlyadhesive murine fibroblast cell line, and Staphylococcus epidermidis, agram-positive bacterium that occurs frequently on skin and in mucousmembranes.

Silver loading in the PEMs could be varied from ˜24.2 μg/cm² to 0.4μg/cm². Cytotoxicity to NIH-3T3 cells seeded on these films wascorrelated with the concentration of soluble silver in the PEMs, withaugmented toxicity at higher silver concentrations, as shown in FIG. 8.PEMs prepared with relatively more ionized PAA entrapped lower amountsof silver and demonstrated reduced cytotoxicity. Further, their stronglyionically crosslinked architecture allowed better attachment andspreading of fibroblasts than PEMs prepared using weakly ionized PAA, asshown in FIG. 10. Bacteria killing efficiency of PEMs correlated to theamount of silver entrapped in the films (FIG. 9), with PEMs containingas little as ˜0.4 μg/cm² of silver providing up to 99.9999% kill in awater-borne assay. Furthermore, PEMs with this silver-loading did notexhibit measurable cytotoxicity to NIH-3T3 cells.

Example 14 Transfer to a Soft Surface with Microscale Beads

Introducing rigid microspheres in the polymer multilayers facilitatestheir transfer onto the dermis layer of a commercially available humanskin graft—GammaGraft®. A PAH(PAA/PAH)10 multilayer, with fluorescentPAH and a PAH(PAA/PAH)5(PS μ-spheres)(PAH/PAA)5PAH multilayer, withfluorescent PS microspheres were stamped onto skin grafts. The portionof the multilayers that adhered to the grafts were accessed byfluorescence microscopy and imaging. The results (FIG. 12) showed thatthe polymer multilayers with microscale beads showed much bettertransfer to the skin graft than did the polymer multilayer withoutmicroscale beads.

All publications and patents mentioned in the above specification areherein incorporated by reference. Various modifications and variationsof the described method and system of the invention will be apparent tothose skilled in the art without departing from the scope and spirit ofthe invention. Although the invention has been described in connectionwith specific preferred embodiments, it should be understood that theinvention as claimed should not be unduly limited to such specificembodiments. Indeed, various modifications of the described modes forcarrying out the invention that are obvious to those skilled in relevantfields are intended to be within the scope of the following claims.

What is claimed is:
 1. An article comprising: a polyelectrolytemultilayer formed from anionic and cationic polymers and being from 1 to500 nm thick disposed on a support selected from the group consisting ofa wound dressing and a biologic wound dressing, said polymer multilayerhaving a releasable antimicrobial silver composition incorporatedtherein, wherein said releasable antimicrobial silver composition isreleasable in an amount of from 0.05 to 0.5 μg/cm² of said polymermultilayer per day.
 2. A kit comprising the article of claim
 1. 3. Thearticle of claim 1, wherein said article is packaged in a sterilepackage.
 4. The article of claim 1, wherein said article does notsubstantially impair the healing of wounds.